Day of defeat is excellent, if you don't mind the dated graphics. They've really gone for historical accuracy.
BF 1942 is great. I love the Market Garden, Tubruk, El Alamein and Iwo Jima maps. Kharkov is also good.
What I don't like is the dubious 'substitutions'. The Japanese with all German weapons, the British without a Lee-Enfield or Vickers in sight and the Russians with BARs and Thompsons?
The planes are fun in their own way. It's like an arcade game of yesteryear with superb 3D graphics.