I keep one game going for each map. When it ends I start/join a new one for that map. Settings vary wildly however and I'll play almost anything. Every weekend I update stats on my performance based on map and game settings.

Best map for me: USApocalypse (not my fave design, but most wins)
Worst ...

When you miss a meeting at work because you lost track of time while playing.

...and then you do it again later the same day.

...and you're the boss.