I looked at the short list(though still quite big) of Web 2.0 Awards winners and looked through the list. I recognised a number of the names, some from this Learning 2.0 program and some from my personal internet use.
There were 2 that caught my eye. Cocktail Builder which has cocktail recipes on the site which users can add more. You can search for those weird sounding cocktails you have heard of but don't know what's in them. There is also a cool feature that you can put in a bottle or 2 of alcohol that you have and it will give you the drinks that you can make with it. It has user ratings for the cocktails and you can add drinks to a list so you can print out the ones you want to make. It would be great when planning a cocktail party. I would have found this a lot more useful about 10 years ago, but I'll probably use it at some point.
Another one I liked was Guess-the-Google game. The maker of Montage-a-google has made a game out of it. With Montage-a-Google, you put in a word and it searches for images on Google Images and creates a montage out of them. Guess-the-Google turns this around to make a game from it by giving you a montage of images and you have to guess the keyword used in the search. It is a cool little game that is a fun way to waste a bit of time.