Orange Box, but seeing as almost everyone else suggested it, I'd suggest these: Defcon-Kind of slow, but you get to Nuke enemy countries. They have a Demo. Mount & Blade-Good, but kind of throws you out into it's world without anything to go on. Also has a Demo. More of a 3rd Person Hack & Slash with heavy RTS elements. Empire at War-Quite fun, you might end up wanting the expansion pack. Can't remember if there's a Demo, but I loved it on PC. Tropico 3-Fun, but might be Offensive. You get your own Island to rule over. Command & Conquer-Can't go wrong with this series. RTS. AVP-While more of an FPS Series, all 3 have great multiplayer, and are fairly Strategic. Get the 1999 one and play the Marine Campaign if you want a Scary game. Evil Genius-You get to take over the world and have your own Island of Doom, complete with Minions, Henchman, and a Laser. Supreme Ruler 2020-Looked interesting, but I haven't tried it. Zeno Clash-Might also be interesting, but not as much of a Strategy game. Edit: Splinter Cell, don't forget Splinter Cell Chaos Theory.
The thing is I don't even play Counter Strike that much. It's a decent FPS, but what you're really buying is Garry's Mod, which lets you do literally ANYTHING that you would think could be done in a FPS game, and some things you wouldn't think of. If you already have a game that runs on the Source engine, like Half Life 2 or Left 4 Dead, you can just buy Garry's Mod alone for $10, then get GTA 3 and Vice City for $10 apice.
Thanks a ton for all the suggestions. Ill check them all out eventually! I bought CS:S, so I have ten bucks left. Thanks again guys, you rock!
Wait, did you buy CS:S alone? If so, go buy Garry's Mod with the remaining 10. It's definitely worth the purchase.
Yes, I bought it alone. I probably shouldnt have, its not quite my type of game. I guess I just have to get the hang of it.
CS:S is much more strategy based than MW2, if I say "garage rush" to my team (whether I know them or not), most people actually rush to the garage, it's much easier to make plans with people you don't know, in MW2 ppl dont listen. Also, you can't get backraped in most maps. Warining: CS:S is about 20 times harder than MW2, you'll need some practice. I'd say: Wait for a good weekend deal, very cheap and awesome games.
Just go use the last $10 to buy Garry's Mod then. That was actually the main reason I recommended the game was for Garry's Mod. It's the best mod to any game ever.