If you're talking flying deployments, most AF are 120 days vs 7-15 months for MC and Army. Of course you can always get tagged for a non-flying year or my personal favorite a year teaching Iraqi pilot training. If you really don't want to deploy, then stay out of the military.

That said, while it hugely varies based on what you fly, when you're at home you're training to go to war. If you never deploy you just spent your entire military career training for something you never got to do. Who wants to do that? (hopefully the guys with nukes, but you get my point).