Screencast app for Mac OS X Leopard

I’m looking for the best screencast software (sound recording is a must have) to run on my MacBook.

So far I found the following software:

• Adobe Captivate 3 [Windows Only]
• SnapzProX
  
• BTV
• Camtasia Studio [Windows Only]
• iShowU
• vcn2swf
• Jing Project [integrates with webapp, by the creators of Camtasia]
• Screenography
• Screen Mimic
• Screen Record
• Blip.tv [integrates with webapp]
• Screencast [thanks Rui Moura]
• ViewletBuilder

From what I have read so far it seems iShowU gathers most of the preferences. But when a app is prefixed by an i mac users seem to love it immediately.

Anyone tried any of these products? What are your thoughts on them? Which one would you advice me to use?

[EDIT: Currently I have tested most of these products and I'm using iShowU and KeyCastr]