DEVON MILES  We value simple, straight forward, easy to use tools like iArchiver here at FLAG. If you're doing anything that involves archives... whether its packing, extracting, or converting... This is the tool I'd recommend.

I have to say betterzip comes very close. But you just can't beat the price for iArchiver. Only $9... That how much I spend on lunch every day!

One feature I'd like to see added iArchiver is the ability to modify existing archives. That would save me from having to totally unpack and repack it.

BTW: it even supports creating DMGs! Great feature! Strange that this is not emphasized more on their website.  
(Version 1.1.2)