Everyone loves a list, right? Well, a lot of us do. We watch Letterman because his top ten lists are funny. We go Hanselman's website for his ultimate list of tools. We love to see what other people find important and compare their lists with our own. I find that lists are a great way to find out about tools and sites that I wouldn't have found otherwise.
For the most part, lists are cool. This is why Listible is cool. Listible is kind of like Digg and Del.icio.us got together and had a really cool baby, and named it Listible. Here's how it works. Basically, someone requests that a list be created to cover a topic. Then the public is free to add items to the list and tag them like in del.icio.us. But what makes this site special, is the public's ability to vote for an item thereby driving it up the list. The public sets the relevancy of all the items in the list. So when you view a list, you can be relatively confident that the best stuff is at the top.
You can even vote for the relevancy of the list itself, which will determine how that list ranks compared to other lists. However, I'm a little unclear about this. I can understand one site being a better .NET reference than another site. But, can you really say that a list of .NET reference sites is more important than a list of Wedding Planning sites? It seems to me that importance is in the eye of the beholder.