Desktop (Win7)- Windows Explorer
- Notepad
- Firefox
Pretty much the essentials. :P
Laptop (OSX)- Finder (because you can't unpin it ffff)
- Firefox
- Tweetie
- Documents
- Downloads
- Trash (see Finder <_<)
You might be able to remove stuff from OSX but I've never figured out how and don't actually look at the dock enough to care that much.