I was just going to say this! I thought their match in Indian Wells, while being one sided, was a great watch. Played a corker at the Olympics and their match in Istanbul was crazy good.
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.
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.
I'd agree with Azarenka-Kerber, their game styles match up really well to produce great tennis imo.
I don't really enjoy this match-up. Yes, there are some interesting rallies from time to time but for the most part I think it's boring to watch two players that are barely able to hit winners from the baseline and often have difficulties to end a point at the net, also everything looks like in slow-motion when they're playing. But I do enjoy watching both up against someone with an aggressive and powerful game.
Their matches this year weren't their best. I liked the Indian Wells 2010 and Stuttgart 2011 matchups particurarly the latter. I'd have to look at the tapes but it was one of the more entertaining matches of 2011 I think.