You could always try the game everyone loves to hate: EVE online.
Space ships, no avatars (yet), fleet fights, sandbox style, real consequences, single server (no realms/shards/separate servers). Everyone who plays plays together
PvP in EVE is somewhat unique. If you get killed, you don't get your stuff back. It's gone, done, blown up, floating debris in space.
Some who have tried it complain that they can never catch up to veteran players. It's all about how you play, not necessarily how good your stuff is.
Check it out: www.eveonline.com
If you want a 21 day free trial, e-mail me through my profile.