I like the originals. I'd say pick from the official maps, list found here (scroll down)
http://counterstrike.wikia.com/wiki/Counter-Strike:_Global_OffensiveBomb Defusal
Aztec
Dust
Dust 2
Cache (became official on July 1, 2014)
Cbble (released on December 18, 2013)
Inferno
Mirage (released on June 12, 2013)[5]
Nuke
Overpass (released on December 18, 2013)
Train
Vertigo (released on October 1, 2012)[6]
Hostage Rescue
Assault (released on February 7, 2013)[7]
Italy
Militia (released on March 21, 2013)[8]
Office
Maybe we could hand-pick a few great workshop maps. I'd say they should be either defuse or hostage rescue. I'm gonna check some of them soon.