For this, I have only counted TV matches, not dark matches or house shows.
Randy Orton:
RAW, November 22, 2010 vs. The Miz. It was a plain old 1 on 1 match, and Miz won clean in the center of the ring without any interference. However people might not count that, since it was Ortons 2nd match in a row (this was Miz winning the belt).
RAW, July 12, 2010 vs. Edge. Jericho appeared on the ramp, which distracted Orton enough to allow Edge to spear him for the clean win.
RAW, December 14, 2009 vs. John Cena. Cena won clean with the AA in the middle of the ring.
John Cena:
RAW: March 15, 2010 vs, Big Show. Batista (whom Cena was feuding with) appeared on the ramp which allowed Show to hit the Knockout punch and pin Cena clean.
RAW: October 19, 2009 vs Triple H. Triple H won 100% clean in the middle of the ring.
Alberto Del Rio:
He's lost numerous tag team matches, but I'll only count singles matches.
RAW, November 29, 2010 vs. John Morrison (2nd round of the King of the Ring). Like a lot of the previous guys losses, there was distraction (this one was Mysterio), which led to a clean win.