Hmm... Bebop I guess.
Cowboy Bebop, Wolf's Rain and Samurai Champloo form an interesting circle for me, all together they contain the elements of what could be the best anime ever, but individually they have a lot of problems.
Samurai Champloo has style but lacks substance. The characters are cool, but kind of shallow, the plot(s) is well paced but all over the place and pointless. It doesn't amount to much but it's a lot of fun
Wolf's Rain has (So I hear)a lot of hidden meaning and substance below the surface, but I never felt connected to the story. The symbolism is far to vague and require to much homework. The characters seem like they could be interesting, but they aren't ever explored enough on the surface, there is a lot of nuance, but it gets so thick that it becomes hard to tell when you're supposed to take something as abstract or concrete.
Cowboy Bebop is in the middle, and I think is the best of the three. The characters supply just the right mix of nuance and attitude to form real human beings, Spike remains one of my favorite anime characters of all time to this day. But that brings me to it's problem, it's still to heavy on execution, and to light on concept. Almost everything about Bebop seems referential. The characters are very good, but they are because they're well executed rather then being conceptually fascinating, they leave an impression, but don't really do anything that's game changing. The plot is very thin on it's own, and is really only carried by the characters in question. The "Filler" episodes are good, but only a couple of them really surprised me in any way, and I often thought about how much more interesting the one shots could be if they had more time to grow on me. I think I had more base fun with Champloo, simply because it kept me guessing more often, but never connected to it's characters like I did in Bebop. I think Bebop has the best balance of style and substance of the three, but it isn't as distinctive because of it, it's just very highly above average in both respects.
The thing is, if these three shows were mad into one, they would all repair the others faults. You'd have the immediate fun factor of Champloo, the hidden messages of Wolf's Rain, and the balance and characters from Cowboy Bebop.
Champloo and Wolf's Rain are actually the creations of people who worked on Bebop, so that might not be so far fetched.