What I use to extract and
mostly PACK files with.
(So why would I need an extract only prog?

)
WinZIP 11.0.7313 PRO
WinRAR 3.70 Corporate edition
WinACE 2.61
And Specially for the ISO's etc.
WinISO 5.3 (I have something with the Win***

)
Magic ISO Maker 5.0.0166
IsoBuster Pro 1.9.0.3
Let's just say that there isn't a package that's un-unpackable for me.
PS. Don't ask me for sources, this isn't the place to answer them.