The Gamecube. It's a shame it didn't get too much attention, because it had some really great titles. Some of Nintendo's best games were on it, and it generally had the best versions of multi-platform titles. I also love the controller, it fit my hands perfectly.
Gamecube. It had some of my favorite titles when I was younger, and even though it wasn't really that much of a step forward compared to what the last generation had done, I really can't give up Pikmin, Windwaker, Path of Radiance, Tales of Symphonia, or Paper Mario.
5. PlayStation Portable: specifically I am referring to the 3000/2000 model PSP systems. The games for the system by itself were great, lots of RPGs and unique games like LocoRoco and Patapon and a decent handful of ports of older games. The newer models however gave me interstellar wood for the fact that you could connect your PSP to your TV to play on a large screen without the need of some clunky 3rd party device. Its that defining factor that makes me rank the PSP higher then the DS which had an equal number of great RPGs and unique style games. I am so very much hoping however that the Wii U allows DS games to be played on a large screen.
4. PC (Windows 95/98 era): this to me was the perfect era for PC games. No required online connection, no real annoying DRM, still able to buy the majority of PC games in a physical version and the games were unique enough to really stand out from the majority of console games.
3. Game Boy Advance: RPGs, side scrollers, top down hack and slashes. Pretty much to me it was the SNES 2.
2. PlayStation 2: This is actually a rather more modern system I would consider a favorite for me, for a long time I hadn't really though about it until I took a step back and looked at all the games I had in my PS2 library. A HUGE selection of RPGs, really well done platformers and a whole bunch of really unique games like Ico and Mister Mosquito. A huge assortment of so many great and original games definitely makes me rate PS2 pretty damn high.
1. Super Nintendo: Because EarthBound. And to a lesser extent all of the other amazing RPGs, side scrollers, puzzle games, etc.
Or more specifically:
0. Super Famicom: the majority of the greats on the western version plus an almost entire separate systems worth of Japan exclusives.
And one I would like to throw out some well needed love for: The Virtual Boy. I love the VB, its one of the only systems I ever played where I ever got a real "oh shit" moment graphic wise. Games like Red Alarm, Mario's Tennis, VB Wario Land and Teleroboxer, all IMO great games, loved the 3D effect and no I never got headaches from playing it or got annoyed by the red color of the graphics. I really wish VB had stayed on the market a bit longer because some of the titles they had planed for it, like F-Zero, a Mario scroller and I believe even an early version of Goldeneye 007, all would of been amazing to play on it. The only reason I don't put it on the list is because there were so few games released for it that I really cant justify giving it a spot when compared to other systems I loved with piles of great games, but then again you cant go wrong with a system that only really had one truly bad game.
Hard choice, but I think PS 1. But also SNES, Genesis and PS 2. Mostly for Final Fantasy, Dragon Quest/Warrior, Lufia, Phantasy Star, Shining titles. PS 1 wins because it is just paradise of RPGs (port of Lunar I, II, Grandia, Tales, Suikoden, Breath of Fire, Arc the Lad, etc. etc. etc.).