7-zip
Takes care of most of your archive extracting/compression needs. Supports ZIP, RAR and many others formats.
Universal Extractor
With over 50 supported file formats, Universal Extractor is superb.
IZArc
One archive utility to rule them all. Supports almost all formats.
PeaZip
User friendly, free and open source archive manager with enough features to satisfy power-users.
Hamster Lite Archiver
Another freeware archive manager with a bold interface and good compatibility.