Here's a quick overview of how webcomics tend to end.
If there is a story, the most common ones are:
1: All's well that ends well. (E.g. The Hope Virus)
2: It never ends. (E.g. Housepets)
3: The story got cut as the creator never actually finished it. (E.g. Over the Mountains and Far Away)
If there is no story, the question is pretty much irrelevant.
As for how I think it should end, there is a variety of options. Though, my favourite is a good ending with a sacrifice. Think of the movie Avatar and the game Dust: An Elysian Tail. Peace is restored in the end, but the peace came at a certain cost. I'd like something like that if I ever made my own. It would be nice to be able to see a bad ending sometime as well, we don't see those too often either.