I've always been a "Class Levels" kinda guy. I came to RPGs via AD&D, and Classes & Levels were my first experience.
Shortly thereafter I was introduced to Traveller. It didn't have levels. Heck, you never really got better at stuff, you just acquired better stuff. (that was my first attempt at houseruling - putting expo and skill increases into Traveller)
My first non-level / non-class RPG gaming experience was Runequest 3 (Avalon Hill). Shortly after finding RQ3 I stumbled on RQ2 discounted at a convention. I liked RQ2 more than RQ3.
I liked the lack of classes and levels in this alternative fantasy RPG, almost as much as I liked levels and classes in my main RPG - AD&D.
I wound up running a RQ2/3 hybrid campaign using Pavis and Big Rubble for the better part of a year (with some AD&D / Traveller gaming mixed in).
I'm getting very tempted to consider putting together a RQ6 game, and all I've done is read the first chapter and skim the rest of the PDF. It really is hitting the right notes in me.
Goddamn Gamer's ADD!
(as a side note - Legend struck none of these notes in me - go figure)