Sega Megadrive. Actually I owned its American sibling Sega Genesis long before I got my first Amiga. I must say this console blew me away - playing Sonic the Hedgehog, was indeed marvelous experience back then in 1991 when most of my friends were having NES clones. I thought it felt like having arcade at home. Except for Amiga, none of my later systems (PSX, Dreamcast, Xbox etc) could rival Sega Gen (MegaDrive) in the "wow factor" category. My fave games were: Sonic series, Virtua Racing, Gunstar Heroes, Robocop vs Terminator, Streets of Rage 2. Later on equipped it with Sega CD (waste of money as the most of FMV games were rubbish!) and Sega 32x.
SNES had its great line-up of RPGs, Donkey Kong Country and mode7 titles, but I preferred that arcade experience only Genesis could deliver.