I enjoy Azarenka-Serena match-ups. Azarenka almost always brings a very consistent level of play to the table, which forces Serena to raise hers. Azarenka-Sharapova is somewhat similar, except if Azarenka is playing at a higher level, its not really possible for Sharapova to quickly shift into the upper gear to beat her. Nonetheless their matches are quite good quality.
Originally Posted by Diamondtieva
Serena-Ivanovic is usually quite well-contested, even though Serena still wins in straight sets.
I think of Dubai '09 and USO '11. Good matches as straight-setters can be.
Serena-Ana is one of the ugliest match-ups. Bar a couple of really flashy winners its all really bad.
Ana with her hack and pray forehand enrages Serena whenever she does make a good fh winner after 50 failed attempts. Serena goes into this 'I will clobber you by showing my forehand is better than yours' tactic and the matches become way more competitive than they should.