Fun tactical shooters

Ghost Recon is a pretty good start. I use to play the multiplayer of this game quite a bit.

Modern Warfare 2!

But not really.

Well, they do have 'hardcore' modes, but I haven't played them.

Rainbow Six Vegas provides some entertaining moments.

ArmA2 is pretty hardcore, might be what you are looking for, esp. the Warfare mode.

Jesse

Thanks for the suggestions. The voice acting for ArmA2 is too hilarious and kind of kills everything for me. :(

I'll look into the others as well, but are there any particular games that have an impressive command chain or communications system?

Ghost Recon and Rainbow Six are the main games that come to mind. Brothers in Arms is also a really good tactical shooter, with an entertaining story line to boot.

Rainbow Six is awesome to play with friends until you've played through every map a few (probably maybe 40 h gaming).

Rainbow 6 Vegas 2 gets my vote. Also, if you have Half-Life 2 installed (or something that uses the Source Engine works I think), go get the free mod NeoTokyo. It is similar to CS, and people play as a team instead of as individuals, it is a load of fun.

Can't believe nobody mentioned Hidden & Dangerous 1 Deluxe (inc. expansion pack). Co-op multiplayer, pre/real-time planning, no heroics (one shot one kill most of the time on your end). And it's completely free.

Click and profit.