I think the only thing I really REALLY can't stand in tracks at this point is sampled phrases of the following things:

-Popular hip hop tracks (even though I've done it once, but at the VERY end of a track)
-Samba/salsa/latin vocal and music loops
-Straight up whole phrases from other tracks that are longer than 1/4th a bar and aren't messed with sonically.

There was this really huge track that everyone and their mother played about a year or two ago that violated the latter two. Think it was Thomaz vs. Filterheadz but it wasn't "Sunshine". Ripped an easily-identifiable loop off from SLS's Tribe Cutz Vol. 1 EP.