I've been playing EvE, on and off, since it first released back in 2003. I'm currently in an off phase, but as you might imagine I've got several high end characters and more isk, ships, mods, and other junk than I know what to do with. The most fun I've had in EvE is with PvP combat, so my suggestion would be to keep running your missions for a while, but try to mix it with some fun.
Red vs Blue is a good place to start, or EvE University, if its still running. With RvB you can join and leave when ever you like, and fly what ever ship you like. Usually people fly tech 1 frigs and cruisers, and use swarm tactics, its mostly in high sec and is a great intro to PvP. Once you've progressed on from this then its time to start thinking about nullsec, either 0.0 or WH space.
If you want to make isk then market trading is probably the most lucrative activity. And you can do it on an alt quite effectively with only a few hours training, and only a few hours per week effort invested. Obviously the more you put in the better you'll do, but even low effort can yield big rewards when you learn the market.
Other MMO's? Well like half the planet I'm waiting for Guild Wars 2, but I'm also having a really great time with the TERA Online beta. Most of it fairly average, and certainly nothing you probably haven't already seen before, but what makes it really stand out is the combat system. Its much more action oriented than your average target / hotkey system. Playing as a melee class turns it into a hack and slash game, while playing as a caster it becomes, basically, a third person shooter. Great fun.