Difficult decision, I really like them all. Which is the one with the nightclub? Plaza? I love that one.
Hijacked is one of my favourites because it's manic, but I've got a lot of love for Carrier.
What I miss is that old COD4 map, 'Bloc.' Hilarious sniper battles and hectic room-to-room firefights in there. Good times. --- "I love finding threads like these, it's like walking outside and finding the city's been bombed while you were sleeping." - Blighboy
Standoff, Raid, and Slums are my favorite. Mostly because I think they're the simplest from a map design stand point (bar Hijack perhaps but the spawns are god awful), you don't have to worry about getting shot from five different angles such as Yemen or Aftermath.