SNES
Genesis had quite a lead in its heyday. It took a couple of years for the SNES to finally surpass the Genesis. However the comparison doesn't quite work because the SNES started off quite strong. I personally think Sony's got a good chance to pull the same sort of thing off because simply because I think this generation will be the longest one we've ever seen. I really don't believe we'll see a new round of consoles in 4-5 years like we have in the past because the 360 and PS3 are already so powerful. On top of that, every successive new generation is tougher and tougher on the developers; more and more of them close down in the trasition (Clover is one example). The third reason is that I believe people are finding it more difficult to justify buying a brand new system. Personally, I would've loved to keep playing my PS2 and GC for another couple of years, and I think a lot of people have a similar attitude. That's why the PS2 keeps selling as well as it did last year. With such short console cycles in the past it was too difficult to overcome an early deficit. Now Sony has much more time to work with.
My Top 5:
Shadow of the Colossus, Metal Gear Solid 3, Shenmue, Skies of Arcadia, Chrono Trigger
My 2 nex-gen systems: PS3 
and Wii 
Prediction Aug '08: We see the PSP2 released fall '09. Graphically, it's basically the same as the current system. UMD drive ditched and replaced by 4-8gb on board flash memory. Other upgrades: 2nd analog nub, touchscreen, blutooth, motion sensor. Design: Flip-style or slider. Size: Think Iphone. Cost: $199. Will be profitable on day 1.
