...What the hell kind of an ending was that?

If you recall how the old man use to sit there everyday waiting, then when everything turns south, Enid goes to visit him and he's gone? I think the representation was to insinuate that Enid had moved on, possibly even killed herself. But it's done in such a way, only the viewer can make up that conclusion.

Agreed. Glad I'm not the only one who thought so. The movie was great for the most part, but the ending was really weak. Even tonally, it didn't seem to know what it was aiming for.

Well, first you have to realize that this movie isn't really a comedy. It's about how some people are unable to deal with life, and that's what Enid is dealing with throughout the movie. The ending is a very good way to demonstrate what happens in that kind of situation. Most of her actions in the movie are either deliberate attempts to avoid growing and becoming a part of life, or failures at actual attempts to mature. The end of the movie basically shows all of this coming to head and demonstrates that it's too much for Enid to cope with. That's why everything is dragging and sulking: Enid is realizing the position that she's in and coming to the realization that she can't deal with life.

As for the bus, it makes a lot of sense when you realize that the old man that had been waiting for it was "the only thing" that Enid could depend on, like death. The old man leaves, probably because he dies (it was stated that the bus didn't run anymore), and Enid taking the bus symbolizes a similar was of leaving. She realized that she couldn't deal with life and decided to try to escape the life that she had, either by leaving, or by killing herself (it's up to you to decide which you think it is), something that makes a lot of sense given the character and her predicament.

the ending of a story that lets you decide on the conclusion is far better than one that spells it all out for you,
come on, story telling is not only supposed to entertain you, its also nice if it makes you think.
what you think ends the story, what you imagine goes on....
and even better your imagination changes the reality depending where you are in life, you may not see that yet, but hopefully one day you will.

I think the bus was a metaphor for suicide. I know that the author and people associated with the film deny this but I still think that's what it was.

I have to agree that the ending of the film lacked the quirky watch-ability of the the rest of the film. Really once Rebecca and Enid's friendship falls apart I can barely remember much of the film.

It's not as funny when you know that part.

From Ghost World's (the comic book) Wikipedia page:
Enid?s eventual fate in Ghost World is not explicitly shown; however, she does pack her bags and leave the city on a bus after her relationship with Rebecca ends. In a 2002 interview[5] Daniel Clowes and Terry Zwigoff were asked if the ending of the film adaptation was a metaphor for suicide. Daniel replied "Yeah, it could be. It?s hard to figure out why people have that response. The first time I heard that I said, 'What? You?re out of your mind. What are you talking about?' But I?ve heard that hundreds of times."

The film is titled "Ghost World" because of the people in the world who are "ghosts"; people such as Seymour who are antisocial and don't leave the house, who really don't exist. Enid getting on the bus symbolized her becoming a Ghost.

I've never considered the ending to be a metaphor for suicide. But I see how you can interpret it that way. And even though the creaters deny that as their original intention I think everybody is allowed to see what they want.