GURPS, Battletech and AD&D 2nd ed. in decreasing order of enjoyment. I have played a few others (MERP and RuneQuest for example) but those are the main ones, and the only ones about which I would claim to be really knowledgable. How much I go for character/story development and roleplay vs. min/maxing really depends on the system; AD&D will always be limited for roleplaying because it began as a tabletop combat simulator and is still largely restricted by those roots, but GURPS almost requires some character development in character creation so you know where to spend your character points. That also incidentally answers the question of creation; with a system like GURPS I spend points on the skills and attributes that fit my character concept, aid my characters success or (ideally) both; with AD&D I put the best of my 4d6 drop-the-lowest rolls in the attributes most vital to the character I am playing then go buy equipment with whatever money I have. With Battletech I am playing a mech rather than a character and usually prefer to design my own with whatever technology is available because 90% of the stock mechs in the Technical Readouts are garbage designed to reflect mass production in a resource scarce world rather than an optimized and versatile design.