HaHa, I know, a bit cliché, at least in MO.
1 – Cavern.
I like this map mostly because it was the first one I’d ever played.
2 – Shrunk
This map has a lot of secrets, and can be fun to play, or explore as a spectator. It also brings strategy to a whole new level.
3 – Invasion
While small and easy to die in, this map looks nice.