that IL 2 Sturmovik Birds of Prey... it's a flight sim, but more on dogfights. also, Freedom Wings is another flight sim with simple graphics, but potentially good gameplay (i say potentially because auto-target makes it too easy, but learning to shoot and fly manually really takes some practice). flying around can be quite fun, as it has respectable draw distance (texture ain't so grand though), but if you randomly roam, you'll get owned by pirate planes.
Then there was that MySims flight sim, which is a ton of fun, but has wicked anti-piracy in it. you can only go so far storywise, and how far you get is random. some people get quite far along, some people only unlocks a few missions, then it stops alltogether. no more new missions. but gameplay is superb, maps are arena like with multiple levels (air, ground level, and sub-ground level areas in one map), and dogfights are impressive for a casual title.