Long time since I posted in these forums, but since no one else brought it up, I want to mention GURPS here. I love the character point system, the various advantages, the various setting books, but my favorite part of it is certainly the skill system.
I don't know any rpg that offers support for as many types of action as GURPS does. And good part of it is in the big skill list, which gives various rules of how different talents can be used. From tactics to photography, from biochemistry to mathematics, the skill system offers many different abilities, suggesting many different types of character, and allowing for many play styles.
The system is obviously not without faults. For example, I have yet to see anyone using math skills for anything other than pre-requisite for some science skill (which would allow the character to design their own inventions, among other things). However, Even skills that don't have much use by themselves by default can be put into play by a clever GM.
