Mainly because I want to try out these polls for myself, but anyway...
Cast your vote.
Anyway, it's a tough call between GC and Other (Sega Megadrive) for me... I'll have to go with the 'Cube though, as I only really play Megadrive games on emulators these days. Was a brilliant system in its heyday though.
PS2 - It's got Final Fantasy and GTA under its belt, so yeah, pretty good.
GBA - Undisputed king of handheld gaming... for now.
XBox - It makes a nice but ridiculously expensive bin if you take all the hardware out of it.