It's more of a prank, but, one I need to solve. When shitty domains get voted up to the Top 10, people will see those and infer the overall quality of the doma

It's more of a prank, but, one I need to solve. When shitty domains get voted up to the Top 10, people will see those and infer the overall quality of the domains on the site. Worse, no one will ever register those domains and they will sit on the Top 10 list forever, unless I delete them manually. So I've got to figure out some way to make the Top 10 list accurately reflect which are the best domains. Currently I'm thinking something along the lines of a popularity equation which uses time and clicks, similar to what HN does with time and points. Thoughts?