Time Magazine has an article about the movies of 2008. Twilight came in at Top 8 as a wild card taking over the spot usually held by action movies.
"The only wild card was No. 8, the teen vampire romance Twilight, which was also by far the cheapest to make, at $37 million: the budgets for the other pictures in the Top 10 averaged about $150 million." Read more.

Source: Time.com