I liked SM better. I thought the storyline was better, and the portrayal of Norman was much more true to the character then that of Ock in SM2. Sans his GG costume of course.
Aside from that, SM2 didn't fix issues I expected them to fix, Spidey's lack of humor, making Peter Parker evolve from less of a Dork, making MJ actually act like MJ...and since they didn't fix those things, it got me angry. Basically it's the same situation I had with the Pirates of the Caribbean movies. Dead Man's chest was good, but not as good as the first. Though, if I hadn't seen the first, I would have probably loved Dead Man's Chest.
If I hadn't seen SM1 I would have loved SM2, but since I saw SM1, my standards were higher and they failed to meet my standards.