Text Editors:

Smultron - free
TextWrangler - free (essentially the same as BBEdit and a slight throwback to Mac OS9)
ForgEdit - free for now
SubEthaEdit - $ - supports collaboration
TextMate - $

None of them, IMO, hold a candle to TextPad for Windows unfortunately. I use TextWrangler right now - if I had an Intel Mac, I'd run TextPad under Windows virtualization.

A fairly cool product that includes the SubEthaEdit core and a very nice CSS editor plus of course a lot of other feaures for managing web projects, is Coda from Panic. It bills itself as "one window web development"

The best archive utility for Mac OS is BetterZip - it costs a little $ but has a nice GUI. It can open, create and modify archives of pretty much any format.