Although I liked both movies, there's so much so wrong with both of them.

I do feel however that Hulk 2003 is more memorable and just taps into what makes Hulk an interesting character to me, and that is the whole Jekyl and Hyde aspect of the Hulk. In TIH, the Hulk is treated more like a disease than an aspect of Banner's personality. If you noticed, he Hulks out whenever he reaches a certain level of excitement, it doesn't matter if it's caused by anger, effort or sexual arousal. At least that's what it's heavily implied by the movie.
But I don't know, the movies are just so different, and meant for different people. I place them at about the same level for the people they're intended to but for me like I said, Hulk 2003 gets the slightest edge. I would say Hulk - 8 and TIH 8,5.