I've only 100%d a few games (not counting games that 100%ing just means getting to the end)... FF4, DKC2, DKC3, SMRPG, Super Metroid, SMW, Kirby Super Star, LoZ: LttP, Star Fox 64, Banjo-Kazooie, Majora's Mask, Diddy Kong Racing, Pokemon Red/Blue... maybe a few more... There's 2 or 3 PS3 games that I got a platinum trophy for if that counts.
I don't... feel much when I do so. It's just for fun in the end. If I had fun doing it, then I'm happy.