Stock maps = largely meh bar a couple good ones like Red Oktober and Grain Elevator. Love the allies losing reinforcements, adds urgency to the battle.
Mamayev stands out though as it's more balanced than those two (No Germans ever attack from their right side, no Russians defend that side, but no one seems to even try to use the right / south side), brings longer ranges - which is all of the fun IMHO. No other game comes close to the thrill a simple bolt action can give me in this game. Mamayev is a bolt action feast, ranges from 35m to 200 are easily found, he who shoots best is he who will do best. I like it.