When I was younger, I hated sampling with a passion. The song that really really bothered me was "Ice Ice Baby" by Vanilla Ice, appropriating the "Under Pressure" sample from Queen. But now, I've grown to appreciate the creative use of a sample.
I think the best one so far is "Sunchyme" by Dario G, almost entirely based on "Life in a Northern Town" by The Dream Academy. This creates an entirely new song, and I prefer the new version to the old one.
Another one that creates a wonderful mood is "Doin Time" by Sublime, based off of "Summertime" from Porgy & Bess.
Finally, this ain't that musical, but collage sampling must be respected as well. "U2" by Negativland, primarily featuring outtakes of Casey Kasem.
What samples do you like?