Wow, Spiderman 3 was bad. Like, walk-out-in-the-middle bad. I didn't bother to look up any reviews because the second movie had been so good, but I should have remembered the sequel half-life rule. The chances of a good second sequel following a good first sequel is vanishingly small... It was as if they couldn't find a decent script, and just took the first three off of the top of the pile, dropped them into a blender, and poured a glassful of the results into a mug. It was about twenty minutes too long, was full of logic flaws & deus ex machina, and was over-crowded with villains. It certainly didn't help that the writers included almost every bad idea ever inflicted on the Spiderman comic, though they managed to resist the Gwen Stacy clone thing. I guess they needed to hold something really bad in reserve for the inevitable direct-to-video fourth movie.
Oh, and Stan Lee? Go home, and stop inserting yourself into Marvel franchise material. I know it's the only thing left to you after the suits bounced you out of control oh so many years ago, but I'm tired of seeing, and worse, hearing from you.