A lot of the apps are not free, and many of those are quite nice. They have a smaller audience, but they are not all junk.
That said, I use several free apps that help me out quite a bit.
- AP Mobile keeps me up on the news
- Epic Pet Wars sucks a ton of my time

- Twitterific gives me my Twitter fix on the road
- Shazam has helped me ID dozens of songs I never would have been able to find again
- Public Radio gives me my NPR-talk-radio fix when all I can get over the air is music.
- Wikipanion gives me fast, easy access to the wealth of Wikipedia
- Light has been the most useful of all. It helped me countless times. Way better than the light from the home screen.
- Enjoy Sudoku is a great Sudoku interface. Better than paper or even than paid versions.
- The Weather Channel has saved my butt more than once, showing me live radar of storms coming my way. Plus the hourly forecast is a great thing to have on the road.
- MiniPiano has helped me work through a few ideas
- iHandy Level has helped me level someting more than once
Hm. That's all that's coming to mind off the top of my head. But no, I most certainly would not call any of the above junk. They are all excellent applications. (Well, Public Radio does cut out too much, but it is certainly worth every penny I paid for it
zero.)