Time Magazine created a list of what they consider the 50 best websites in 2007. Here's a link to the first of the web services sites in the list. Unfortunately, they don't provide a simple list of 50 sites on a page. You have to endure clicking through the sites one at a time. Gag...

Time Magazine 50 Best Web Sites 2007 - Web Services

Not all of services mentioned are free (e.g., Mozy). However, some favorites of mine (Tumblr and Twitter) made the list.