I'll stay away from pairings of two great workers, it's rare that two great workers don't click but it does happen.
Mark Henry as a heel and Randy Orton as a face had great chemistry recently, surprised me because I thought those two could've gone either way. Mark Henry and Big Show worked well together too.
Batista and Cena had great chemistry.
Edge and Cena, each is a top 3 opponent for the other guy imo, their 06 feud was one of the best things post-attitude era
Goldberg and Scott Steiner