It's true. I really do think Cowboy Bebop is overrated. Is it horrible? No way. CB has one of the best soundtracks ever, one of the best English dubs ever, and has Spike, a very interesting protagonist. Other than that . . . it really doesn't have much going for it.
(Note: there are some major CB spoilers up ahead. If you care about CB and haven't seen all of it yet, don't read further.)
I got started on Knocking on Heaven's Door, the CB movie. It's kickass. I then saw the tv series on Adult Swim, thinking it too would be kickass. Of the 26 episodes produced, I'd say about 6 of them were kickass, like the movie. The other episodes were either boring, and/or incredibly cliched.
"Wait! CB isn't cliched! Do you see giant robots in it!? Do you see character designs that look incredibly unrealistic!? ARE THERE J-POP SONGS IN THE SOUNDTRACK!?!?! NO!"
No, that's not what I meant. Except for the character of Ed, CB doesn't have any cliches you see in Japanese pop culture. Hell, personally, I think CB should've been done in live-action. There's nothing in the show nor movie that couldn't be done in live-action film. (Although I don't have my hopes up for the actual live-action CB movie currently in production, either.)
What I mean is this; CB rips off American cinema. So much so, most of the tv series was completely predictable to me. You see, I'm more familiar with American cinema than I am with Japanese animation. You may not suspect it, but it's true. How else could I have named off all those classic films a few posts ago? Because of this, CB was so cliched, it was beating on dead horses to me. Note, I said, to me. Maybe not to you. Most CB fans I know are "real" anime fans who have abandoned Western pop culture, so perhaps to them, CB is fresh. Unfortunately, it wasn't to me. Even the CB movie had me thinking at first, "This is a lot like a Quentin Tarantino project, but with a lot less swearing."
I only saw the entire tv series because I forced myself to. Only because internet denizens would not. Fucking. Shut. UP. About CB's supposed "godliness." If I followed my heart, I would've abandoned CB after the 4th or 5th episode. It was just that monotanous and cliched to me. Granted, it's not bad enough to be on my master list of anime I hate, but it is certainly no Eureka Seven, either.
And the fabled ending? I would've liked it, if it wasn't so hackneyed. Now, its ending is unusual for a tv series. However, I've seen several movies and games with a similar conclusion. Anime otakus, the idea of a hero not giving a damn about himself anymore and killing the villains in a reckless and selfless manner has been done before! It's not 'unexpected', it's hackneyed! But hey, at least CB's ending had good music, and a sense of finality to it. I'll say that much.
A lot of people like CB for its style. Especially the music. Maybe that's why the manga adaptation wasn't well received. I read one of the manga volumes, the one supervised by Shinichiro Watanabe. It was basically a couple of typical episodes without the music, without the animation, without stuff like that. It wasn't very enjoyable, aside from a few wisecracks from Spike and Jet. Take away the style, and you don't have much substance.
And yet, it's not completely worthless. The episodes I did like show that the creators obviously have talent. And the movie was really cool. And CB does have one of the best soundtracks ever. (I have MP3s of some of the tracks.) Spike is cool, yet vulnerable in a believable manner at the same time. I do own the movie on DVD.
I can't give a solid rating for CB the series, because the quality of the episodes varies so much. If most of the series was like my favorite episodes, (examples: the first one with Ein, the two-parter on Jupiter, Mushroom Samba, the one with Cowboy Andy) I'd easily score it an 8 or 9. However, most episodes were no lower than a 4, but no higher than a 6. And yet, the CB movie I would give a 9.
However, when I do my lists of favorite anime franchises, please don't act surprised to see that CB is not anywhere on there. There are reasons for its exclusion. Also, I did not get into Samurai Champloo for similar reasons.
LATE EDIT: I did eventually give a rating for CB: 6/10.