I give it to Sharapova vs Mauresmo
Both matches had some good quality tennis in there and some tension and excitement, but for me the Kim vs Justine result had a bit too much predictability about it. I expected Justine to get a tough match and then win in 2 sets and she did so it lacked a bit of fire for me.
The Amelie vs Maria match had many more elements of unpredictability to it - Maria never having beaten Amelie, would Amelie overcome her demons or would she choke a lead away, etc. The tennis may have been, at times, lower in quality than the other match but it made up for it in the drama stakes. It was just a bit more gripping, the intensity of both players was present. Kim, on the other hand, was mostly quite passive and unexpressive.