Check out the list of top 100 Wikipedia pages. Here’s the top 10 pages from the English site over the past few weeks, aside from the main Wikipedia page itself, with average views per day in brackets:

1. Wiki (862,286)
2. Harry Potter and the Deathly Hallows (394,000)
3. Naruto (384,000)
4. Guitar Hero III: Legends of Rock (378,286)
5. United States (315,429)
6. Wikipedia (314,286)
7. Deaths in 2007 (306,857)
8. Heroes (TV series) (293,143)
9. Transformers (film) (290,000)
10. Halo 3 (287,143)

One interesting thing is the huge diversity in the pages that people view. The top 100 pages combined (including the main Wikipedia page) make up less than 6% of total page views on the English Wikipedia.