#50 - Command & Conquer: Red Alert 3 (Kudos to Scoobes & Veknoid for guessing this)
Multiple reasons why this particular C&C made my list over many other entries in the series (and I have left off a number of C&C games which I really loved). The co-op campaign was a fantastic step forward - it was an enormous amount of fun for me to play through the whole game with a good friend of mine; we had an absolute blast. The "land, sea and air" combat was as good as it's ever been with Red Alert; and the storyline - although completely nonsensical - was incredibly amusing. Like I mentioned in my clue, seeing Tim Curry among others completely ham it up was just insane. In fact, I think it may have my favourite monologue from any game ever:
All in all, a fantastic RTS and a fantastic return to form for the series after the abysmal Tiberium Wars and even more abysmal Tiberium Twilight.