The standard BOMArchiveHelper.app built into OSX's finder is ok for simple compression and decompression Zip operations. If you're looking for replacements that can handle more formats, such as Tar-GZip, Tar-BZip2, Rar, 7-zip, LhA, and others then try some of my favorite free ones:
If you consume much content from the usenet newsgroups, then you will definitely want a set of programs that can recover missing information by processing often used "par" and "par2" files, and recombine sets of files. The best combinations I've found for this are:
Suttfit Deluxe is a good classic Mac compression utility as well, however it does sell for $80.00.