It's too bad the Kokutitas match in the semifinals of the 2006 Mickey Mouse Open wasn't at a Slam. Pretty stellar shotmaking to be found (although Theodoros coughing up 2-3 errors per game isn't a good look, admittedly).
ok, ok. Serious stuff now.
If we're looking at
dominance, that seems to suggest scoreline more than anything to me. And there, the AO 2007 SF thrashing would have to stand supreme. Problem is that Roddick played one of his worst Slam performances, and while Fed's shotmaking was absolutely stellar, there are a few matches that stand right up with it (whether they surpass it, you tell me) but because they were against better-playing opponents, the scorelines don't look as convincing. Ergo, similar level but lesser dominance.
One such example is another match against Roddick, the 2003 Wimbledon SF. Roddick played pretty well, actually. He wasn't completely embarrassing himself, and while he didn't hit the heights he achieved in the 2004 and 2009 finals, I think he put in a respectable-enough performance. But Fed was
crazy good. Forehand, serve, volleys, footwork, speed, anticipation, touch, and even the backhand all combined to create one of the best performances ever at Wimbledon IMO. I've hyped this match up before and for good reason. He hit 60 winners to 12 unforced errors in those three sets as per these stats (
https://tt.tennis-warehouse.com/index.php?threads/federer-roddick-wimbledon-2003-semi-stats.597325/) which is a scary good ratio. Tennis Abstract adds a few more errors to the count (which is 56-23) but they're usually very strict on those. Still extremely solid numbers all around.