To name names, "Killing me softly" by DJ Dave, and "Nothing's gonna stop us now" by Mandy & Brandy (both from the Trance of the 80's, Vol. 5 album; disc 1, tracks 3 & 4) suffer badly from this tendency. Both of those get going with a good, fast beat, and sound like they're going to build into a decent dance song, then come to a screeching halt and break into an undanceably slow verse, then jump right back to top speed, then hit another brick wall, and repeat ad nauseum. Thereby completely ruining the mood and feel the song keeps building up to and greatly annoying me when I thought I was going to get to listen to a fast & peppy dance song.
Feudalism: Serf & Turf