Oh, forgot to mention some I've added recently:
Snapture - a camera App, better than the built-in one. Used to only be available for Jailbroken devices via e.g. Cydia, but is now on the App Store.
Redlaser - barcode scanner. Scans & IDs barcodes, & searches online for the best price. Works quite well. The devs release betas for free on Cydia, prior to then releasing the final version as a paid-for App on the App Store.
Layar & Wikitude - Two separate
Augmented Reality (AR) Apps.
JB-wise, I have:
SBSettings (process/memory info & memory freeing; on/off toggles for WiFi, 3G, etc.; App shortcuts & other tweaks & customisations)
Winterboard (theme manager - I just use it for the transparent dock option at the moment).
Five Icon Dock
Five Column Springboard