I'm currently completely obsessed with Warhammer Fantasy RolePlay. The importance of magic items became annoying for me in DnD, so I'd probably play something like the Black company rules if I used d20 again.
Finding another game to play doesn't mean you're "disillusioned" with 3.x, any more than having a slice of chocolate cake means you're disillusioned with cheesecake.
We are still playing the same game we started in 3.0 and moved over to 3.5 when it came out.
I have played only two characters and DMed only about 8.
We havent even begun to try all the classes/combo/senarios there are.
So we have a long way to go before getting bored/disillusioned.
And for the record I am having a blast. Maybe the best gaming time ever.
I'm currently running two Eberron campaigns, both with 3.5 rules (and minor house rules), and just joined another game (using 3.5 rules) as a player. And I'm enjoying myself thoroughly.
I wouldn't say I'm disillusioned with 3e per se but I'm definitely digging Iron Heroes right now. I'm playing in one game and hope to start a MB game of my own in month or two...
I had to go with the "something else entirely" option. I don't actually run anything produced by some one else. I developed my own system based on a point buy/xp expenditure system inspired by the Champions/Hero system using D% resolution inspired by the Rolemaster/MERP system.
Playing is whole different story though. In which case the games any of my friends run are a hybrid 3.X with slight house ruling.