X2 and X3 are probably the only games in which I never even came close to the end (hardly paid any attention to plot missions at all, really) and still loved them dearly. I sunk hour upon hour into just cruising space, getting into the occasional skirmish, trading, ferrying people from station to station, discovering little things here and there. It feels so ridiculously, massively big and "alive," and yet for me at least, the "play it your way" thing really held true. I never felt like I was being punished for not pursuing a particular path or trying to grow beyond a certain level; I was just dropped into the universe and left to my own devices. It's a bit dense, yes (pre-X3 games, anyway) but worth the effort if you dig that sort of free-form gameplay. (And the graphics and soundtrack are absolutely lovely too.)
