Yup, Mastotron and IE Oxide are my two weapons of choice, the Oxide is a versatile beast.Fuzz pedals all have a baked in sound so it's hard to recommend one and be confident that you'll like it. The Z.Vex Mastotron is my current favorite and is pretty affordable. I also have an Iron Ether "Oxide" and a 3Leaf "You're Doom" that are also good with active basses.
I've just started using the Brassmaster side a lot, it's raised a few eyebrows and shook a few rumps.