Well I'm going to jump right in and say that I feel that this film was the poorest of the franchise.
My main beef with the film was "what was the reason for 6 different plot-lines happening throughout 1 movie?"
(Stop reading here if you haven't seen the movie yet...)
I felt that they "cheated" with the opening credits by inserting footage from the first two instead of using the traditional illustrations and paintings I personally enjoyed.
The weak introduction of the alien symbiote really annoyed me. (Very convienant for that tiny meteor to land there wasn't it?)
Sandman was treated poorly during the movie. I really enjoyed the animation during the introduction of the character, but the rest of his screen-time really wasn't experimented enough. (I didn't know Sandman could fly.)
Harry Osborn's Goblin 2.0 character seemed wasted as well. He had all the moves at the beginning of the film, but convientantly lost his memory so the movie could concentrate on the other 5 story arcs. His skills do come in handy during the big battle scene though...
Venom was wasted in this film I thought. Only one big battle with the evil character and his film career was finished. (Hopefully there is someway to bring back this awesome character, Carnage maybe?)
There was a lot of slow spots in the film as well. I know that this is necassary to get the characters emotions across but we already know about them, less talk more action.
Along with the bad is some good though.
I liked seeing Gwen Stacy on the screen finally. Her character seemed to be plopped in for convience though.
I enjoyed watching Peter fall victim to the alien symbiote. Spidey became more of a bad-ass which was great and Peter Parker's bad attitude was a refreshing change of pace.
I highly enjoyed Venom alot. He was handled well. I even accepted Topher Grace as Eddie Brock, a nice twist from the original "big muscled" character. The design and character animation was really cool to watch.
All in all, the movie is watchable and fun, but it's not the best thing to come out of the Spidey trilogy. There was a scare that this was going to be the last movie, but why cram so much into it? It seemed that the Venom storyline was well thought-out while the Sandman storyline was there for filler.
If you are a die-hard Spiderman fan like I am, you will be disapointed and left wanting more from it, no question. But if you are looking for a (I hate to say it...) fun, popcorn film, check it out.