Personally, I have loved Spiderman since before I could read...
I liked the first film well enough, and still think the second was maybe the best film ever, but Spidey 3 was not quite as AWESOME as I'd hoped- as mentioned above, the main gripe I had with it was the pacing (especially since possibly the best sequence in the whole film is in the first 20 minutes or so)
Still, pretty good fun- I won't get into details, but if you liked the first two, I'd think this one is a safe bet, it's both funny and kinda spooky, and Franco as Harry Osborn was truly great in this outing, I've liked the way his character was dealt with so far but I think he might have been my fave character in this film, totally hilarious yet oddly subtle job of bringin the insane "best friend" to life