I'm a guitarist/keyboardist as a hobby, in that I know that I'm not good enough to be part of a band, but I'm okay with that - I do it for fun, and as a stress reliever.
As far as influences, I'm a rock guy at heart, but I'm into more experimental types of music as well as calmer, gentler music.
Specific examples of people/bands that have influenced me - this is not the same as my favorite-bands list, though all of my favorite bands are on this list; there are even some bands on here that I don't particularly like or listen to anymore, but I know they've influenced how I play (Oasis is the best example of this). I also tried to put them in the order I discovered them, but I'm sure I didn't get that quite right:
The Who
The Beatles
Led Zeppelin
Queen
The Rolling Stones
The Doors
Pink Floyd
George Harrison
Jimi Hendrix
The Kinks
Tenacious D
The Polyphonic Spree
Red Hot Chili Peppers
Oasis
Secret Machines
Beck
Bob Dylan
David Bowie
Cream
ELO
The Flaming Lips
Radiohead
They Might Be Giants
Bob Marley
moe.
Umphrey's McGee
Arcade Fire
Dirty Projectors
Bedouin Soundclash
The Black Keys
Brian Eno
Philip Glass
Fleet Foxes
Grandaddy
Medeski, Scofield, Martin & Wood (all together and separately)
Simon & Garfunkel/Paul Simon
Mumford & Sons