Well, as some of you might have guessed, IMO the inbuilt zip functions in XP suck. They don't let you do half the stuff that WinZip and other do - I've never been able to make a self-extractor with it, or am I missing something?
WinACE is OK, but IMO WinRAR has a far superior GUI.
But I still stick to 7-Zip, cos it's free and handles, uh, everything. And does everything. And is generally excellent.
http://sourceforge.net/projects/sevenzip/