Have always done my own, with pencil and paper. Was considering using one of the tax preparation programs, but after checking them out they still don't quite seem ready for primetime when it comes to overseas returns.
My tax situation should be a fairly simple one, except for all the weird-@$$ stuff that gets thrown in the path of people with lives abroad for no good reason that I can see. I've had 40-odd-page filings, with zero tax owed at the end -- what purpose does that serve anybody? But no, god forbid I should be taxed as a non-resident, just because I am a citizen.
I admit I kind of enjoy the puzzle-solving aspect of doing one's own taxes, up to a point. But it gets to be way too much after a while, and my fuse is getting shorter every year.