OiNK changed my life. I discovered it in high-school and found so much good music that I never would have experienced otherwise. I still think about it at least a few times a year.
WhatCD was pretty damn good, I'd say it rivalled Oink. Remember the bounty on that MSFT forensic tool? The copy of the unreleased JD Salinger novel? Both fulfilled...
What.cd was certainly better than oink in terms of the library (largely because it was started by seeders who already had the entire oink library) but was definitely missing the charm.