By definition (from wikipedia) a one-hit wonder is an artist generally known for only one hit single. But then, let's face it, not all one-hit wonder artist suck or only has one good hit. Some of them even was just 'forced' by their record companies to release a single commercially for the record companies' own reasons.
But then, some artists really have ONLY ONE GOOD HIT/TRACK. Here's my short list:
EMF - Unbelievable (I love this track, but then the rest of Schubert Dip album suck. Never bothered to listen/buy the other releases after it.)
Spacehog - In The Meantime (just like EMF, I bought it's debut album (Resident Alien) because I love the first single, only to find out later that it was the only track that appealed to me.)
Indeed!