This is the best version of Spider-Man. There's a huge cast of characters in both Peter's and Spider-Man's life, but there's also a great deal of cohesion and clarity. This is especially apparent thanks to almost all of the villains having origin stories, and most of the supporting characters appearing regularly.
Almost no one just pops up out of nowhere. Peter gets a job at Curt Connors's lab, for instance, which is also where Eddie Brock and Max Dillon work. That's three big characters introduced that we get to know before you-know-what happens. At OsCorp, Octavius is established as an employee of Normal Osborne's, while Adrian Toomes is established as a business rival (again, before you-know-what happens). That's three more major characters introduced and their lives explored. And it goes on and on and on like this.
We get to see both sides of the lives of these characters, and it makes for an elaborate yet utterly cohesive viewing experience that fans can enjoy like a serial drama even though most episodes are standalones. Not just that, it makes them far more fully realised characters. After all, a hero is only as good as the villains he fights.
The people in Peter's life aren't just props, either. There's a well established social order at his school presented in the first episode that gradually changes over the course of the show, and a genuinely interesting love rhombus develops that even a chap in his mid 20s can enjoy. There are often parallels and contrasts between goings on at the school and goings on in Spidey's life that mesh, albeit subtly, very well.
One annoying oversight is that Black Cat isn't given an origin, yet her physical abilities seem easily equal to Spidey's. What was up with that? Spider-Man himself also isn't given an origin until later on in the series. I presume this was because we all know how it happened, but also to throw us right into the action. They do show it, though.
The presence of supervillains in the first place is also really well explained. The Big Man of Crime (whomever that may be!) concludes that when Spider-Man is occupied with supervillains, his army of petty thugs goes unnoticed, leaving them free to be bad guys. This is a great explanation and the show actually takes the time to explain it, which shows just how much the creators cared. Many villains come from this idea, with others being accidents, but everything feels connected.
Spider-Man spends more time focused on bringing down The Big Man's crime empire than he spent focused on Kingpin in the excellent (but now, frankly, redundant) 90s version. This becomes more interesting as other major players become involved, all vying for position as the city's crimelord.
Speaking of the 90s cartoon, this version of Spider-Man is ONLY a Spider-Man cartoon. No X-Men, no Blade, no Dr. Strange and no Madame Web. It's very grounded, and it's all about Spidey. It was made for the fans, not to sell toys. That's probably why it only lasted 26 episodes, but it's a blessing it was made at all. Gone are the army of robots, too, like the Spider-Slayers. While many laser-guns are still used, the creators kept this to a minimum, and some real guns are shown and used on occasion. It's no Batman TAS, but it's better than Spider-Man TAS.
The writing can take a while to get used to. On the Spider-Man side, it's extremely sharp and clever and the banter is as witty as I've ever seen it (for example, in one scene Spider-Man drops a traffic cone on Rhino's horn, and says "I got the thing on the thing! What do I win?", Rhino turns to him, irate, and says "You!". Spider-Man responds "I win a me? That makes no sense at all!" - that makes me laugh every time), but there's a lot of dialogue on the Parker side that, although it retains its more-than-just-for-kids-style, is definitely written to appeal to the youth of today, leaving people born in the 80s or earlier feeling a little alienated. That being said, it works well and probably will grow on you, and there's some very mature humour, such as Black Cat making a reference to Spidey's web being a bit like something else a lad his age produces in vast quantities.
The art style can also take a bit of getting used to, but after a few episodes it becomes clear why they went the way they did. The art is very clean and simple, and while that may not work for you, it has some clear benefits. First of all, all of the characters are extremely identifiable by silhouette alone, which makes everything extremely clear, even during its most hectic moments. Secondly, the simplicity of the art style allows for some amazing speed of motion during the action. The fights are truly spectacular, and it's the art that makes that happen. There's also a very soft colour palette, which I find very pleasant to look at, but maybe that's just me.
On the sound side, there's some fantastic sound work (the scream that accompanies the Green Goblin's pumpkin bombs is absolutely perfect), while the fast paced rock that accompanies action is perfect, but also blends into the background where you barely even notice it. The voice cast is singular, featuring the voices of people such as John DiMaggio (better known as the voice of Bender from Futurama), Clancy Brown (the most underused great actor in the world, his presence is spectacular) and Tricia Helfer (Six from Battlestar Galactica). Some of the cast are professional voice artists, while others are screen actors branching out, but all are magnificent.
So, the flaws. There are only 26 episodes. It's been cancelled. It's over forever. That's the only problem with the show. What's on the screen is nearly perfect. The only other superhero animation that can compare to this is Batman TAS, and if I had to choose, I'd pick Spidey. As far as these DVDs go, it's pretty poor value for money in terms of quantity. There are only 3 (or 4) episodes per disc, and while they are cheap individually, there are 8 to buy. If you buy them all, it works out to about £40 for 8 hours of entertainment and there's not an extra to be had.
It's more than worth it.