I'll play just about any class. I can have fun with all of them. But I certainly have ones that I prefer.
Me too... i've played almost all of them at some point...
Funny thing is how much fun you can have while playing a class that is not "on top of your list".
I tend to believe that i'm more openminded and "unoccupied" when i play... say a dwarven fighter, or a paladin...
When i play a Wizard or a Rogue... i somehow feel that i "have" to play to the best of my abilities, because i know more about how those classes work...
Just for the story of it... here's my list of prefs.
1. Rogue/Wizard. 
... ok and since that doesn't count... its either one or the other...(it's probably the Rogue...but i can't admit that to the "wizard" in me..
2. ...
3. Bard or Ranger. Although i've played a couple of bards in 2e i 've never tried a 3.x bard... lots of flavor...
The Ranger is perhaps the best martial class IMO... lots of flavor too..
4. one of the above. ...
5. Druid. Perhaps i like him as much as the ranger...but when i want to go "natural" i don't want spells to be a major part of it...
6. Paladin. RP wise he can range from crap to gold. Make him fight with his inner self and you've got diamonds in your hands... Anti-Paladins are wonderful story elements.. Lord Soth (DragonLance) is my most beloved villain by far.
7. Fighter. While considered a 2D class... there are so many and diverse ways to play a fighter...some good multi-class value as well IMO. Always fun to play one...
8. Barbarian. ... Well Conan is in the hearts of as all. Never played one though... Still i enjoy them in games.
9. Cleric. Ok... now that's a class i don't really like...NEVER played one. I still believe that he's great... that he can be quite varied... great villain value (even more than the wizard IMO)... it's just not my thing... besides... i've always played in games where there was at least one guy who was CRAZY about taking a cleric...
another thing i don't like about the cleric... it feels like he has no weakness... too good in lots of stuff without a real downside.
10. Monk. not my thing at all... I don't know if that was an attempt to incorporate the AMAZING Inquisition clerics of the middle ages... ("The name of the Rose" book AND movie).. ... but in case that was their intention, they've utterly failed... clerics can be that, if one wants Inquisition-ness in his game... and they are much better at it.
If i'm missing the point and the designers' intention was to bring some "orientally" into the core books... well that's not my thing either. I personally hate "theme-mixing".
11. Sorcerer. Now... that's a class i truly hate. I 've always played magic a certain way (both as player and DM) in my games. Magic is somewhat rare... requires study.. hard work... Arcane magic is a "science" of sorts... finding a new spell means it's time for celebration... Now... bringing in a guy with some... "dragonblood" that lets him do magic like its... so easy... well it's not my thing...
there... you have it....