I owned a few systems while I was growing up. They're all special for one reason or another, but my two non-Amiga picks have to be my Amstrad 6128 (now dead, sadly), and Sega Megadrive. I can't even count the number of hours spent in front of them.
Honourable mention goes to the Neo Geo Pocket Colour, for being the underdog who dared to take on the Game Boy, and was actually better, but nobody realised. 80 hours on Card Fighters is not the kind of commitment you normally make to a handheld!