Well I already am that so... :lol

Kamen Rider... Wizard!

http://www.youtube.com/watch?v=vYZMqN26U0o

So, wait, what about Den-O then? Momotaros only possessed Ryotaro by chance, and if you don't live their life, then that doesn't confirm you'll get Ryotaro's Imagin should you choose Den-O...

Kintaros. He spends most of his time napping. :p

true that but you might end up meeting them in diffrent way not how ryotaro met them

You end up in the same circumstances up until they get the driver. For the purposes of this topic, you would end up possessed by Momotaros, Urataros and Ryutaros

I call dibs on being dark kiva.

Joker!
https://www.youtube.com/watch?v=5gYAkcscCxo

I'm changing mine to the only Rider Series I've watched every episode of of.. three times.

http://www.youtube.com/watch?v=_un4wlyyenU

I'll be awkward and pick G. Just cause I think he's awesome and needs a series (kamen riders equivalent to akibaranger maybe?) =p

In case that doesn't count I think I'd like to be Fourze. I can go to space, come back from the dead if my friends are sad and I can have an item for any situation. On the slopes but forgot my skis? No problem, board switch. Running late for work? Cosmic's warping ability.