I went into it with extremely low expectations based on a family member's review, the critics, and my own let-down after Spider-Man 3...but I came out loving it.
I thought it was easily the best of the series. I can't wait to see it again.
I'm really surprised with all of the negative reviews, too. Some are saying there's no plot, while others say there's too much...I don't know. I thought it was great. Much, much better than the second one, and even a little bit better than the first.