Spider-Man is my favorite super-hero of all time. I've read the comics (mostly the Ultimate comics, but some of the 60's comics as well), played some of the video games, and watched the cartoons (The 1994 and 2008 series being some of my favorite animated shows of all time).
I enjoyed Sam Raimi's Spider-Man trilogy (yes, even Spider-Man 3). When I heard that the series was being rebooted, I wasn't happy to hear about it. My expectations were neutral as time went by and when I walked out the theater, my expectations were blown away.
I don't want to compare this movie to the original trilogy, but I think it's necessary to see where this movie improved from the originals.
Let's start with the casting. Andrew Garfield is a great successor to Tobey Maguire. I can really relate to him like I always do with other incarnations of the web slinger. Emma Stone as Gwen Stacy is even better than Kirsten Dunst as Mary Jane Watson. Gwen is a much stronger character and the chemistry between her and Garfield as Peter Parker is believable. Rhys Ifans is great as Doctor Connors (a.k.a. The Lizard) and I like how he is a "Jekyll and Hyde"-type of villain (kind of like a few other villains... yeah). Martin Sheen and Sally Field as Uncle Ben and Aunt May, respectively, are also great as well. All the characters are portrayed very well and are believable.
The visual effects and the action scenes are good as usual, but nothing new.
The musical score by James Horner is also great, although I prefer Danny Elfman's score in the original trilogy because they felt more memorable and left a lasting impression. But, who knows? James Horner's score may grow on me over time.
If I have to name some complaints, it would have to be that some parts were rushed (although it's a minor nitpick) as well as a couple of parts not evaluated much. I think an extended cut of the movie would be necessary when it's released on DVD, but that's just me.
Overall, "The Amazing Spider-Man" is a fresh new start on the franchise. It has superb acting, thrilling action scenes (especially the climax), an amazing score, and being faithful to the comics but at the same time taking liberties to make it more interesting. Best Spidey movie ever? It's too early to tell but maybe. It's definitely worth watching and I am looking forward to the sequel.