I haven't picked up Call of Duty yet, but KoTOR is the best game I've played in a long time, easily the best I've played this year.
IIRC my first play through took up about 40 hours or so, doing a good deal of the side quests(playing through on the light side) my second play through took me around 30-35 hours(doing all the side quests I had found at that point, dark side), my third and fourth time through the game took me about 25-30 hours to play through again doing pretty much all of the side quests. No multiplayer, but IMO the game has more replay value then any single player RPG I've ever played. There are so many different choices you make that change the course of events in the game, how your character ends how good chunks of the game play out that it really is worth playing through multiple times.
Storyline is stellar, they could make a movie out of the basis of the storyline in the game and I think the overwhelming majority of people would say it was far superior to that of the current trilogy.
I am biased on this issue, if you can't figure out by my handle I'm a big Star Wars fan, that said KoTOR is hands down the best SW game I've ever played and one of the best games period.