The other recommendations are awesome.<p>For me, I like using a lot of desktop window management, however the Mission Control transitions are too slow for me, with the fact that are bulky and uncustomizable.<p>There is TotalSpaces2, which basically is similar to Ubuntu/etc spaces, but you can customize the transitions, hotkeys, locations, etc. Even though I don't have any transitions (so my switching is instant), you can have cube transitions, etc, very similar to Gnome. Downside to the program: $18, with a trial. If you miss proper desktop management, do it. Combined with Spectacle (A tiling window manager), I have functionality similar to XMonad, so I can use my mac effectively.