I don't know about RTS games when it comes to that sort of thing (I prefer sci-fi in that genre), but if you're looking for an actual "wargame" instead of the latest iteration of Team Deathmatch, try out this mod for Battlefield 2 (which you can pick up for $10 now).
Site:
http://www.realitymod.com/
Trailer:
http://www.youtube.com/watch?v=P0GERzdn-mU
Collection of Havok guncam reels (since you brought up the Apache earlier):
http://www.youtube.com/watch?v=cld2j1ycykg
I've been playing that since close to when it came out and I'm still struggling to find a better multiplayer FPS. It's got depth, variety, an awesome community, and a growing number of different factions that are represented across it's growing selection of maps (which are on a completely different scale from most games). Now I have to warn people, this game is absolutely brutal in terms of difficulty and learning curve, but once you get used to it there really isn't anything quite like it.
If that's not your thing, try out ARMA, ARMA 2, OFP2 (when it comes out), or any of the original Rainbow Six games.