As a short intro: (Actually it's long...)
(Took it from www.bleachportal.net)

A zanpaku-to is the direct reflection of the power of its wielder, a shinigami's spiritual pressure given physical form. While they mostly look like any other katana an old-time samurai might carry around, zanpaku-to are far from normal. The foremost difference is the ability of zanpaku-to to harm shinigami. Since shinigami are really a kind of ghost, normal blades and weapons can't touch them. In fact, "zanpaku-to" literally means "soul cutting sword."

So, let's start from the laed character himself followed by a brief discussion of each captain and vice-captain...

1. Wielder: null Kurosaki Ichigo, hero-
Shikai: . He can translate Ichigo's spiritual pressure into tangible energy. The resulting crescent moon of light is called "Getsuga Tenshou" (Moonfang Skyshock) and it can slice cleanly through anything; rock, buildings, people. However, Ichigo is still working on mastering this particular power. Strangely, Zangetsu is constantly in his Shikai form
Bankai: As for Tensa Zangetsu's ability, he takes everything that most bankai put into being big and translates it into speed boosts for Ichigo. The boosts are big enough that Ichigo can launch Getsuga Tenshou from two totally opposite sides of a target *almost simultaneously*
2. Wielder: Yamamoto Genryuusai Shigekuni1st Div. Captain, overall Captain of entire 13 Divisions
Shikai: Yama-jii sets Ryuujin Jakka on fire. Flame sprouts from the hilt and blade, wrapping around Yama-jii in one huge conflagration. The blade itself remains in his hand, though it's hard to see through all the flame.
Bankai: still unkwown
3. Weilder: Soi Fong 2nd Div. captain,
Shikai: . It stings you once and leaves behind a large, butterfly-like mark called a "Houmonka" (Bee Rune Flower) where it hit you. Should it sting you anywhere in that mark again, you keel over dead-- no exceptions. And the marks don't go away until Captain Soi decides they do.
Bankai: still unkwown (or was it shown already?)
4. Wielder: Ohmaeda Marechiyo 2nd Div. Vice-captain ,
Shikai: Ichigo breaks this one really fast, but from what I could tell, Ohmaeda turns Gegetsuburi into a giant mace of some variety
Bankai: does he have one?
5. Wielder: Ichimaru Gin 3rd Div. Captain ,
Shikai: The blade extends at a bullet's speed to whatever length Captain Ichimaru decides. The attack is not just a piercing one, however. Since Captain Ichimaru still has the hilt in his hands the slightest twitch of his wrist can translate into lightning-quick slicing swings by the tip of the blade.
Bankai: unknown
6. Wielder: Kira Izuru 3rd div. Vice-captain
Shikai: . Any thing or person Wabisuke hits doubles in weight. So if you block his strike with your own blade, yours just got 2x heavier. Continue this across the fight, and your blade will end up weighing several hundred pounds. If he cuts you, *you yourself* double in weight.
Bankai: probably doesn'y have one
7. Wielder: Unohana Retsu, 4th div. Captain
Shikai/Bankai (still unknown):Instead of eating you, Minazuki *heals* you in its stomach. Of course, you do still get covered with sticky goo and it still has to vomit you out, so it's something to rather do when unconscious.
8. Wielder: Kotetsu Isane, 4th div. Vice-captain
Shikai: Itegumo's blade splits into three, one vertical and two coming out of the hilt at 45-degree angles. What Itegumo can do is as of yet unknown.
Bankai: none
9. Wielder: Aizen Sousuke, 5th Div. Captain
Shikai: Aizen the power of 'complete hypnosis'. As long as opponents can see him, he can hypnotize them into seeing or believing anything he wants them to.
Bankai: unknown
10. Wielder: Hinamori Momo, 5th div. Vice-captain
Shikai: Tobiume can spit out fire-balls with enough oomph to put an 8-foot diameter hole in stone walls.
Bankai: none
11. Wielder: Kuchiki Byakuya, 6th div. Captain
shikai: Captain Kuchiki makes Senbon Zakura's blade disappear. It isn't gone completely, it has just disintegrated into millions of tiny, razor-thin metal petals you can only see when they catch the light and wink, like the quick flutter of falling cherry petals.
bankai: A stately double row of dozens of swords lines up out of nowhere around Captain Kuchiki and then dissolve into the wind, making that much bigger of a razor-petal cloud for him to use
12. Wielder: Abarai Renji, 6th div. Vice-captain
shikai: Zabimaru is not a sword, it's a *whip*. The plates are joined with a flexible material that can extend incredible distances. Renji can mentally control the length of the whip, but it still takes some weapons finesse to control it directionally.
bankai: Like Shikai Zabimaru, Hihiou Zabimaru is a whip, it just has a much, much larger range. Instead of having a flexible material joining the rib segments, all of Hihiou Zabimaru is held together by Renji's spiritual pressure, so it's nearly impossible for an opponent to sever it.
13. Wielder: Komamura Sajin, 7th div. Captain
Shikai: , a ginormous version of his own hand and Tengen sweep down on opponents from whatever direction he chooses.
bankai: Shikai Tengen a body to go along with the hand, and gets a whole lot bigger. It's an unbelieveably huge warrior dressed in ancient armor and a horned helmet.
14. Wielder: Iba Tetsuzaemon, 7th div. Vice-captain
Shikai/Bankai: unkown (his sword is tucked in front of his kimono)
15. Wielder: Kyouraku Shunsui, 8th div. Captain
Shikai: Katen Kyoukotsu is, along with Sougyo no Kotowari, one of only two zanpaku-to that has a twin-blade Shikai
Bankai: unkown
16. Wielder: Ise Nanao, 8th div. Vice-captain
Shikai/Bankai: unknown
17. Wielder: Tousen Kaname, 9th div. Captain
Shikai: Captain Tousen then sweeps the blade across in front of himself and leaves behind a blur-trail that resolves into a forest of blades, which then hails down on the opponent like a literal blade-rain.
Bankai: Enma Kourogi expands into a giant lightless dome. Not only can no one inside see anything, they also cannot hear, smell or sense anything
18. Wielder: Hisagi Shuuhei, 9th div. Vice-captain
Shikai/Bankai: unknown
19. Wielder: Hitsugaya Toushiro, 10th div, Captain
Shikai: Hyourinmaru itself stays pretty much the same, but grows a long chain off the butt of the hilt with a crescent-shaped blade attached to the end. Both dragon and chain radiate such a chill that any water, even the moisture in the air, starts to freeze.
Bankai: The most powerful known water/ice-elemental zanpaku-to, Dai Guren Hyourinmaru includes not only a moving ice-floe, but also independently mobile ice-stars
20. Wielder: Matsumoto Rangiku, 10th Div. Vice-captain
Shikai: Haineko is in the same group as Senbon Zakura in that it's Shikai form is pretty much invisible. With the trip-phrase "Unare!" (Growl!) from Morimoto, Haineko's blade puffs into a cloud of smoke.
Bankai: none
21. Wielder: Zaraki Kenpachi, 11th div. Captain
Shikai/Bankai: none as of now
22. Wielder: Kusajishi Yachiru, 11th div. Vice-captain
Shikai/Bankai: don't know if she has one
23. Wielder: Kurotsuchi Mayuri, 12th Div. Captain
Shikai:Ashisogi Jizou paralyzes the motor nerves of whatever living thing it hits. It doesn't matter what part of the body is struck, the paralysis moves through the body like a poison until the victim is completely immobile.
Bankai: The most dangerous part of the Bankai, that mist is a specialized poison Konjiki Ashisogi Jizou makes from Captain Kurotsuchi's blood. One good lungful of the stuff is lethal to any living thing within almost two hundred yards of him.
24. Wielder: Kurotsuchi Nemu, 12th div. Vice captain
Shikai/Bankai: unknown
25. Wielder: Ukitake Juushirou, 13th Div. Captain
Shikai: However, it's Shikai is like but one other blade, Katen Kyoukotsu, in that it is two blades in one set.
Bankai: unknown
26. Wielder: Shiba Kaien, 13th div. Vice captain (deceased)
Shikai/Bankai: unknown (we didn't have a chance to see this...)

Now, after my LONG LONG EXPLANATION, the one I like best is Hitsugaya's. He owns the greatest ice elemental sword that I can't resist to love. XD

SPOILER (click to view)

il be an ass since it will come up in the next 5 episodes, i like rukia's shikai and also Madarame ikkaku's shikai AND bankai

Rukia shikai is the best!!

SPOILER (click to view)

maybe Hyourinmaru is the strongest ice zanpakutou but Sode No Shirayuki have a lot more special moves!!First Dance,Second Dance,all of them are some beautifull moves by Rukia-chan!!i can't wait till the fight Rukia against Kaien ,i hope Rukia already achieve her bankai!!

raitei

rukia shikai is the best!!

SPOILER (click to view)

maybe Hyourinmaru is the strongest ice zanpakutou but Sode No Shirayuki have a lot more special moves!!First Dance,Second Dance,all of them are some beautifull moves by Rukia-chan!!i can't wait till the fight Rukia against Kaien ,i hope Rukia already achieve her bankai!!

SPOILER (click to view)

Rukia i think refused the rank of vice captain (or captain) i don't remeber but im sure of the fact that she reached bankai.

I have no idea i guess i'll go with ichigo's Zanpakutou

Sorry but i have to give it to the ash cat of Matsumoto Rangiku, 10th Div. Vice-captain a nice body and a killer mood to match shes my number one

Oooh. Good explanations. I don't remember some of those though. There are a few more if you watch the anime; theres some guy who makes a weird rainbow shikai. yeah. But good job.^^

I have no idea what your really talking about but Aizen's Zanpaktou is friggin awesome. that power is like unstoppable and you dont even know he's like actually using it. well at least the characters in the show dont.

DaAF

I have no idea what your really talking about but Aizen's Zanpaktou is friggin awesome. that power is like unstoppable and you dont even know he's like actually using it. well at least the characters in the show dont.

As much as I hate to admit it, I have to agree. It isn't destructive in a physical sense but it's subtle power makes it even more dangerous than Old man Yamamoto's as seen in the Soul Society Arc.

There are still a lot of captains that have yet to show the power of their zanpakto like Kyouraku Shunsui(w/c is my fav captain) so this could still change, we'll see.

Gee, thanks for the compliment. I had a hard time posting all the characteristics since i had to summarize what I have.

Heck, I knew Rukia's zanpakuto too but I forgot the name. I've read it in the manga and I was hoping to see it in the anime. Or maybe it's shown already? I've stopped watching ever since Bounto series started and just resumed watching a week ago.

Kick-ass sword is owned by Aizen... I wonder how Ichigo would handle it...

Anyways, I'm still a Hyourinmaru (Hitsugaya's sword) fan for life...

...Zaraki's...its gonna be a freaking pirate bankai...thas what i say.

I prefer Kuchiki Byakuya's Senbonzakura Kageyoshi and Madarame Ikakku's Ryuumon Hoozukimaru.

Byakuya's symbolizes one of my favorite aspects of combat, disengaged combat where the wielder itself does not fight. Hopwever, I would probably have prefered the large towerlike blades over the individual petals.

Ikakku's is also a good one symbolizing the purity of power. It basically does nothing for anything other than raising power to insane levels.

However, Ichimaru's Shinso is also a favorite of mine. I just love long katanas and while Shinso is inherently short, it can extend to unspecified lengths.

As for me, i liked hitsugaya's bankai, just because it looks good

Definately Ichigo's Bankai, incredible speed wins the day in Bleach !!
Rukia's shikai is pretty cool... the fractured mask she fought was sooo weak Zzzz

God help us if Aizen show his bankai o.O

Ichigo's bankai speed is so fast that he can leave after images which even as how fast Byakuya is he can't leave after images. but speaking of Byakuya his bankai technique "Senkai Senbonzakura Kageyoshi" is one of my favorites because just being surrounded by swords. I guess Toushiro's bankai too because my favorite mythical creature is a dragon and last but not least

SPOILER (click to view)

Ikkaku's bankai with all the insane power lol.

i don't really have any favorite shikais but i never seen them all yet but i just can't wait to see what Kenpachi's shikai and bankai is going to be i know people are saying that it's already at shikai but i thought it couldn't be until they know the zanpakutou's name. Aizen will be another tough one when he eventually shows his bankai