We should keep this thread to ones that are working 100%, not iPhone ones ported to the iPad.
Having said that, my must haves are:
SBSettings (Beta version is updated for iPad, works great) - Allows you to change settings on the fly by swiping the status bar. Change brightness, toggle Wifi on/off, free up system RAM
Backgrounder - Allows you to multitask, great app.
MultiIconMover - Allows you to select multiple app icons and move them as a group to different pages. So much better then Apple's implementation...why can't Apple work like this from the factory?