Eve online had me for 3+ years Freeform, social, sprawling market system, competitive. Rewards thought, discourages or punishes lack thereof -- which was the hook for me. Start up an achura and fly around in a little missleboat for a while.

Run missions, look at the market see if playing it holds any charm for you. The endgame content is pretty fun, as it is largely focused on your skill and the skill of those you associate with versus those that you fight. A great player behind a 1 month old account can actually be very dangerous to even old accounts.

A small group in eve can make a large impact(ie change the political landscape), which was very rewarding to me. Burn eden was a perfect example of this -- a major force with ~20 players total. Smart tactics and good group comps make a huge difference. I always liked the idea that planning, contacts, and patience paid off. And that you could always walk away with something to learn from a loss -- always watch local, have a scout in the next systems, etc.