[Sailor Steve]

For WW1 it's probably Over Flanders Fields or Rise Of Flight. I haven't played either one yet because of my dreadfully old computer, but I've read all the literature and seen the videos.

ROF is by all accounts the better "flying" experience, being capable of full flight dynamics including torque and wind problems. Just keeping the plane in the air can be a challenge, so you'd better have a good stick and pedal setup. The bad news is that it's designed for online play, so there is no real campaign system, or so I've heard.

OFF is supposed to be simpler and easier. It's a complete rewrite of Microsoft's Combat Flight Sim 3, so you'll have to get a copy of that first. The good news is that they're very cheap these days. The other asset of OFF is a complete campaign system, similar to but improving on the one in Red Baron.