What was the game(s) that sold you on each system you've owned? They have to be games you bought at the time you purchased your system.
Here are mine:
3rd,4th,5th gen were Super Mario
xbox - halo, dead or alive 3, oddworld
gamecube - luigi's mansion
ps2 - galactic wrestling, rygar
xbox 360 - elder scrolls iv
wii - super mario galaxy
ps3 - little big planet
pc - elder scrolls skyrim
3ds - pilotwings resort
psvita - it was a gift