I picked up the habit of saying, "For fuck sake!" Then, when I was going to be taking my nephews and niece camping I realized I needed to clean that up, so I started saying, "For the love of Pete!" Only downside is people keep asking me who Pete is.

I also have used "drat" in the past. Seems like there was another one, but I can't remember it. I do say, "Gah!" a lot. Although most places I am I feel perfectly comfortable cussing.