This is coming from someone who played them (excessively) previously to the point of 10 hour days all summer long and then years later for just a few hours here and there.
Stick to games that when you turn off, are off. Not one you're falling behind in because you aren't there. As a once hardcore gamer, I play games occasionally like CoD4, Diablo2, WarcraftIII. Something you can play for a half hour and have fun (or more occasionally). These are fun to kill some time with, but when you play games like WoW, it takes a significant part of your life that you could generally devote to something well... more rewarding.
That's not to take a shot at hardcore gamers, but when you are playing a minimum 15 hours a week just to remotely keep up in the MMORPG gaming world where you are already 10,000 hours behind.. it's no longer about having some fun gaming.