MacZealots has a great list of the top 10 shareware for OS X.

There's some great stuff on this list that's free. I really like MenuCalendar Clock which puts a nice calendar in your menu bar. (has a free and paid version... will integrate with iCal or Entourage)

I've been waiting for a program like FetchArt for a while now. It will automatically add album art for selected iTunes songs. It still has some rough spots, but works relatively well.

Cocoalicious is a cool client-side del.icio.us ...er, client. I've heard of it before, but haven't downloaded it before tonight. I will have to look into it further.

I have the free version of VooDoo Pad and it is a pretty cool wiki-esque program.

I've heard of OmniOutliner but I really need to check it out. The description on this site makes it sound different than how I've heard it described previously.

Overall it seems like a very good list, though I'm kind of surprised Quicksilver didn't get a mention. It is the single best application I have ever used on any platform, hands down. It's why I will never be able to use anything but OS X for my primary computer.

What are your favorite apps on OS X?