I would consider System SHock 2, Fallout, Morrowind to all be classless games since you define a player character based on the skills you develop not the class you choose.
In a classful game, your class defines the skills you are permitted to develop.
<{POST_SNAPBACK}>
Oh, I'd call them classless too, but that still doesn't change the fact they're built around certain class....errr archtypes
And to appease people who say "Well I beat it without a class....errr archtype"... There's two ways to beat classless games...
The right way and the other way.
The other way is the like the right way but slower and less certain