Do you prefer having a bath or a shower?

Shower, mostly due to conveniance. Though there might be thoughts of stewing in one's own juices in the tub, I'm guessing so long as you use enough soap, the vast majority of dirt will come off and stay in the water. =D

Also, how often do you grab a bath/shower?

At least once or twice per 24 hour period. They're somewhat relaxing and clean any sweat or dirt that might accumulate. I kind of feel like a new person after a decent shower.