Every week day...first thing in the morning! - Its my daily routine.
Two or three times a week - you can really push your muscles to the limit with enough weights, have a little variety from just bodyweight and have better possibilities for cardio training.
And, last but not least, I like the atmosphere and the group experience :-)
As often as I can because of the variety of exercises that can be applied and because it puts me in a "zone" to really kick my ass. Depending on how good you wanna look it's not a necessity though.
Go to edge fitness
I consider a gym membership almost as much a necessity as a refrigerator in this modern life.
I go two to three days a week. Would go everyday but have my youngest at home with me. The days i miss out i usually go for a jog or bike ride in the afternoon.