Apple has created a "Best of 2008" [iTunes link] section in the iTunes Store. On this page, Apple lets everyone know what the top-downloaded TV Shows, Music, Movies, Apps, Podcasts, and Audiobooks are.
Among the top paid iPhone applications are Koi Pond, Texas Hold'em, and Moto Chaser. Among the top free iPhone applications are Pandora, Facebook, and Tap Tap Revenge. There's also a top downloaded podcast list. We didn't quite make the top downloaded podcasts list, but hey, there's always next year.
So, if you're looking to find some of the best online content for 2008, look no further than iTunes. You can click here to visit the iTunes Best of 2008 section.