The acting was really good, and I felt the actors all portrayed their characters well. I thought that Tobey Macguire made a really good Peter Parker and a decent Spider-Man, James Franco was really good as Harry Osborne, and I think I'm one of the few people that thinks Kirsten Dunst made an alright Mary Jane Watson. They all had great chemistry together. You could really imagine that Mary Jane was the girl that Peter loved, and that Harry was his best friend. The father/son relationship between Harry and Norman Osborne was pretty believable. All the actors just worked really well together, and I believe good chemistry works really well toward making a good movie. Even the supporting characters are perfectly cast, like Uncle Ben, Aunt May, J Jonah Jameson and Betty Brant seemed as if they were straight out of the comics.
The storyline is pretty cool, being filled with lots of drama, and you get to see Peter feeling different things throughout the movie. Guilt, love, confusion. You get to see the transformation of a nerdy, weak teenager into a powerful hero. It's not just about some kid who gets bitten by a spider and becomes a superhero, it's got a whole lot more depth than that. And for the most part, the actual storyline doesn't just feel like filler until the next action scene. That's part of what sets it apart from a lot of other comic book movies. Some of the dialog in the movie is a bit cheesy, especially some of the stuff between Peter and Mary Jane, but I don't really let it bug me.
The action scenes are really good, although a little fleeting for the most part. They just seemed over too soon sometimes. They were still really cool though, and were definitely some of the high points of the movie. The costume designs are really good as well. The Spider-Man costume looks awesome in about 132 different ways. Apparently the changes that were made to the Green Goblin costume in comparison to his comic counterpart caused some problems with fans. I think the changes were necessary to avoid being too cheesy. And his new costume looked awesome anyway. The special effects in the movie were pretty good, especially in scenes where Spidey is swinging around. There are some scenes where it does look a little fake, but it shouldn't take away from the movie for people. But I know people do like to whine about every problems in movies, so some people might find the effects an issue.
All in all, it's an awesome movie, and we were lucky enough to get two sequels to it. I've watched it a few times, and it holds up well. A fairly re-watchable movie. It was one of the movies that helped start the modern Marvel movie trend, along with X-Men and the Blade movies before it. Just another great thing it had a hand in. Sam Raimi is a great director. Spider-Man is a great character and was really done justice in a movie that could have easily been awful.