Construction is a fun spin-off from Valve's "Team Fortress 2". Zombies! is a fun spin-off from Valve's "Left 4 dead". Deathmatch/Team Deathmatch is a simple and known concept which alot of games have.
However, nothing beats Standard.
Standard is the way Counter-Strike is ment to be played, and so is CS2D. It attracts the more serious/professional gamers/players and can really be intense when two skilled teams collide on a good map, it requires skills, tactics, strategies and teamwork and so forth in order to win your team the round/match (and definately with fog of war).
Construction sometimes gives you a lot of free time. When I'm blasted, I can mess around and no one will kill me. Construction. It's when you have a lot of time and patience.