I look at my bookshelf and see about 20 different RPG systems. EarthDawn, Palladium, d20, HackMaster, Gurps, WW (mostly Exalted), Villains and Vigilantes, and on and on and on.
I love the Game. I like playing RPGs in any form they come, whatever the rules, whatever the setting. Barring games that suck because they are just extra stupid ( i.e. FATAL), I'll play just about anything.
My wife, OTOH, likes to play d20. She doesn't want to learn new rules or try different games. She loves this particular game. She likes everything about it and sees no reason to try new games.
Which are you?