OK, I'll play.
Systems are nigh-irrelevant, IMO. My itches are scratched with great GM's, great stories, great characters, and people who are fun to hang around with and are into the game. I've played with the best, so my standards are ridiculously high. Since it is important with such games for the system to provide some structure and adjudication but otherwise stay out of the way, lightweight systems work best here, or midweight systems with a lot of handwaving. Savage Worlds, BRP, Dread, Mutants and Masterminds, Paranoia, all have given me joy. The best thing about 3e (and there were lots of good things about 3e) was that so many people knew it so well. Even a moderately complicated system can be very unobtrusive when the GM knows it like the back of his hand.
Now for those times when the GM was not one of the greats, and the plot and characters are tedious, give me a nice tactical combat system so I can kill sumpin. Mini's and maps, tiles and dungeon dressing work best here. 3rd was fine, but 4th is really nice. If Pathfinder is essentially 3rd with bug fixes, then I'm sure it will be fine.
My favorite is still Shadowrun, but mostly for it's setting and atmosphere. The system was interesting, but I ran it for a year and still had to flip through the books during combat. If Paizo comes out with a spellpunk-themed version of Pathfinder and licenses it to WizKids or whoever is holding onto the Shadowrun IP, I'll be their biggest fan. (And yes, I know about Urban Arcana. It's fine, but is missing too much of the flavor. I need my spell drain mechanics to be happy.)