Z Wins

[Rainshadow]

  U as in a ukulele-playing, unicycle-riding underdog with a unibrow.

[SilentSam]

U as in Ugly

[Rainshadow]

  (You actually were supposed to post V, so I'll skip that one.  )

  W as in wet water.

[SilentSam]

Oh lol srry 
X as in X-ray

[Søren]

Y as in yellow.

[Rainshadow]

  Z as in zI win! 

[SilentSam]

A as in A new begging

[Rainshadow]

  B as in bazooka.

[Lady Amber]

C as in Carrot Cake.

[SilentSam]

D as in done, (NOT)

[Lady Amber]

E as in Egbert the Scholar.

[Delthion]

F as in fallacious, false, failure.

[Rainshadow]

  G as in Gamzee.

[Lady Amber]

H as in Healthy Hotdog.

[SilentSam]

I as in I