I like Last for music which you can use without setting up a login, and you can look at other users who are listening to what you are listening to, even if some of them look a bit scary! If you select music to buy it gives you a choice of itunes or Amazon. I also like Farecast for travel.
Overall the list of awards gives you the picture of just how much Web 2.0 stuff there is which is really overwhelming if you try to be an expert on all of it. I like the site that lists the awards as a list of applications to use so I would say the best site is the award list itself, especially if it is updated every year.