I think you're right on, ckmlb. Every time I pop Motorstorm in, I can't get rid of the smile on my face.
I have the exact opposite experience with F1.... but in a good way. I love F1 and sim racers, and this game can be relentlessly difficult, but incredibly satisfying.
I haven't really gotten into Super Stardust, but I never really found Geometry Wars to be very good either. On the other hand, I think Everyday Shooter is absolutely brilliant. It's more of a casual shooter that's incredibly unique. As the title of the game suggests, it's a shooter for playing everyday. And that's exactly what I do.
Finally, I wish more people played Calling all Cars online! The game is just a riot to play. Why didn't this game take off?
Not saying the other systems are flawed or anything, but I think the PS3 has some great variety and am really loving it
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.
