I've been playing this sci-fi browser MMO called "Ogame" for the last few months and it's actually amazing. The name isn't very good, which is why I almost didn't play it, but it really is a huge part of my life now as I'm checking in every few hours to make sure my planet isn't under attack or whatnot. It's kind of like a browser version of EVE I guess, though I've never played it.
If you like sci-fi stuff, give it a look. It deals a lot with resource management, building defenses and fleets, and PvP.
I play on the Draco server, and my name is Afro... So give me a call!