Verified answer

Well, you can only get Tiberium Wars, or both. Since Kane's Wrath is an expansion, you can't get it standalone.

Try the demo for Tiberium Wars first and if you find that you like the game, buy Tiberium Wars. If you liked the demo a lot, buy the double pack containing both games.

Trying the demo first also lets you find out whether your computer can run C&C3, avoiding a major bummer if you buy the game and can't run it/them.

If for some reason your computer can't support C&C3, C&C Generals and its expansion Zero Hour (which have considerably lower hardware requirements) is another fine choice if you like the fast-paced C&C style of RTS in general.

kanes wrath by far its the same as tiberium wars but theirs more stuff you can build and train

You can move into Sins of a Solar Empire if you like RTS ( real time strategy ) games.

But I kinda like Battlefield 2 / 2142 and also SWAT4 or Unreal Tournament 2004/2008

They're all fun =) Those are the best to kill time and have fun while you're at it lol.. sorry if mine weren't new!

Call of Duty 4 is awesome as well.