Counter Strike Source
Remake of the old 1.X map de_vegas (original credits below). Stayed true to the original layout. Nearly all the old angles are still there. Changed a few secrets, and added a few more. Most changes to the map are purely visual.
A mix of two types of map - aim and defuse. Terrorists are trying to bomb target, which is in the middle of the map. And once again - counter-terrorists are trying to stop them. Fast map. 4 on 4 players recommended.
Veikko is an highly detailed, industrial bomb/defuse map for CS: Source. It contains indoor and outdoor environments using default textures and volumetric fog. Recommended for up to 24 players.
DE Velvet East offers many doors, hallways, outdoor passages, and 2 bomb sites.
Villa Cocaina is a bomb/defuse map for CS: Source made by G.I.Joe. This map was originally intended to be a single player Half-life 2 map.