I find it irritating to see that Gulbis is not mentioned anywhere here. Agreed, the occasions whence he has been "on" have been few and far between for the last few years, but lets recall a few proofs of him just simply having some of the best, if not the best groundies in the world:
The Robredo Beatdown, 2007 USO - takes down Tommy Robredo 6-1, 6-3, 6-2 in a mind-blowing forehand display. Link here:
http://www.dailymotion.com/video/x3381x_ernests-gulbis-v-tommy-robredo-high_sport
Madrid Open 2008 - loses a close match to Nadal in 3 sets, backhand on absolute fire. Link to it:
http://www.youtube.com/watch?v=btYGqak2_bM&feature=PlayList&p=7C27D1DD5066E3CB&playnext_from=PL&playnext=1&index=10
Breakout on the Big Scene - Rome Semis 2010 - pushes Nadal to the brink with a broken forehand, nearly beats The King of Clay with nothing but a backhand, a serve, a bucketload of dropshots, and sheer guts. I think we all know where to find this.
If we were looking at the rest of his game, this year's Delray Beach Final against Dr. Ivo could be mentioned as maybe the best return of serve display this year, and the Rome Semi was an awesome show of serving for both firsts and seconds.