In no particular order:

• Doug’s iTunes actions adds several useful new options for mucking about with music files.
• Video recorder lets you save live video images from an attached camera directly to your hard disk.
• iView Media Pro actions will come in handy for users of that excellent media cataloguing application.
• Cut and Paste — OK, not actions as such, but very simple workflows for working with clipboard data.
• Create thumbnail poster grabs a bunch of images, thumbnailizes them, and creates a ready-to-print poster. Nifty!
• View items in Terminal takes the input (or, put another way, the output of a previous action), opens Terminal, runs vim, and displays it there.
• Upload to Flickr; well, you can guess what it does.

Got any more?