"I have no games to play" will probably never happen again in my life. So it's more "Oh hell, what to start next?"

There are not many specific games (ok, maybe Quake) that I return to in this situation. In general I will go through my list of cherished oldies and pick one according to mood. Might be Indy 4 or Monkey Island or Broken Sword... or MoO2 or MoM or SMAC... or even "let's see what new Doom ports there are".

In this case, I start buying games for compensation

Doom. Always. I love deep and rich RPGs or strategy games as much as anyone. But when I don't have much time, or don't feel like sinking 3 hours into a session, or for just the hell of it... there's always Doom. Sometimes a guy's just gotta relieve some stress by strapping on a shotgun and heading to Mars to kick everyone's ass.

Now... if I had some dough and more space in my garage it would be the arcade cabinet version of the original Double Dragon. I can play me some Double Dragon any time. Punching Abobo off a cliff never gets old. Games like Double Dragon are like 80s action movies. It's cheese, there's not much to it, but when nothing else seems like the right thing, silly ass ninja fighting is always a good fix, and the only thing more fun than watching it is doing it in a video game. It's kinda like a drug, really.