Despite claims from previous posts. It's really possible to play:
Command and Conquer The First Decade
Command and Conquer Tiberium Wars
Command and Conquer Kane's Wrath
Command and Conquer Red Alert 3
Command and Conquer Red Alert 3 Uprising
in a Intel GMA 950. I played all these, through the end of each campaign, no problems, even with the most grafic intesive effects (like nukes in TW).
But you have to do some tweaking.
Generals and Generals Zero Hour, I'd advise that you play on low settings to avoid random crash.
TW, KW, RA3 and Uprising: set the resolution to the lowest possible, but don't choose 800x600 if you have a widescreen model, because it will crash. Set all options to the lowest possible, and then, set Shadder Detail to Medium (just one step higher), and that's it. You can play all these, like I had.
[EDIT] You can add Command and Conquer 4 Tiberian Twilight to that, just tested myself. Just set all video settings to the lowest possible and use display resolution 800x600 (otherwise you will run out of vram and the game will crash!). Use gmabooster to improve FPS.
Just as a comment: the game is quite playable with this set up, but the FPS could be better and the graphics look kind of crappy...