I voted Saturn, because it was a huge success in Japan, with it's games outselling Playstation ones, and because the Saturn was really just taking off with it's greatest titles coming out House of The Dead, Burning Rangers, Panzer Dragoon Saga, and Shining Force III all hit at once, and showed the systems true power, it was on a roll, and that's when Sega of America decided to kill it......
Although the Saturn did very well in Japan, even there Sega stole away the two titles that would truly push the system even further than could of been imagined and truly piss all over the Playstation showing a technically superior system dose count. These games were Virtua Fighter 3 and Shenmue which looked absolutely brilliant for a 32bit system.
The Dreamcast also deserves my vote, and probably more so though, it's been noted by many websites and gaming mags as the most underrated system of all time. NEC's graphic chip really did do wonders, and saw the Dreamcast push some ofthe smoothest and most crisp graphics you could possibly want and for it's time was such a huge leap over it's competition the PS1 & N64 with actual textures being introduced instead of just flat polygons with images pasted on them. The system was mind blowing, and for it to have such a short life was nothing short of a crime. In fact the system was killed off so early we would never get to see the systems full potential, the DC is a system I will forever miss.
But like Tynstar said, it's a pity to see so many Sega systems up there... well maybe not a pity the 32x is there.... the poor man's Saturn? Yeah, maybe if it was a hell of a lot cheaper.
But heck, I was one of the few that actually enjoyed all those FMV drenched Mega-CD titles. It was something new, and I was amazed at how they could even have movies and anime like that in a game haha.