Tiberian Sun. I made my first and so far only Origin purchase and got the entire Command and Conquer set for myself. Tiberian Sun was probably my favorite of the series from a gameplay perspective. 3 is great, but there's a little too much modern RTS in it some days; Tiberian Dawn's age and minimalism occasionally frustrates; RA 1 is better in some ways but on balance not quite as amusing.
It was also, I think, the last game with good music. While the height of RTS music and Command and Conquer music was obviously Red Alert 1, with pretty much no bad tracks and several that are evocative like nothing else I've ever heard (to this day, one of my standards of comparison is Run), Tiberian Sun's music managed to be almost as good while being suitably different and atmospheric to its setting. And I doubt I'll ever hear
Valves without wondering where the sidebar is because it's time to do basebuilding, or
Deploy Machines without thinking "oh god CABAL core defender".
I do notice that they've tinkered with a number of the balance features for the is release. I remember the Orca bomber being a part of the game as early as the attack on Vega, and certainly by Hammerfest, but I haven't unlocked it yet. I also think I should have Orca Carryalls by now. I have some very fond of memories of going "lolstrategicmobility".
Conversely, Seeker drones are every bit as much bull**** as I remember them to be.
