I love Modern Warfare and World at War.
Out of the two, I'd have to go with World at War though, it was the first Call of Duty that I got 10th prestige legitimately in and the only one which I've gotten it legitimately in.
Definitely black ops 1 doesn't get enough credit for the most important ideas it brought into cod. Theatre, money for leveling up, buying whatever, good zombies. To much to explain the memories. All games after were utter trash.. Ps xbox is gay nowadays
Mine would have to be COD 1.1. The very first cod to be released and have been playing since it came out. Just a perfect game to play in the cod series.
I couldn't choose between either CoD4 or WAW. Even though theyre corrupt now, back when they were the best games when they were new. They were so much fun and for the new cods they should just refer back to those games.