Bogart & Bergman? Bogart & Hepburn? Davis & Crawford? (Those are just three of my favorites--"Casablanca" and "The African Queen" and "What Ever Happened To Baby Jane?") I probably could go on all day.
Of the ones listed, I was tempted to choose Newman & Redford, but I chose Powell & Loy. They were brilliant together.
Susan Sarandon & Geena Davis in Thelma & Louise. Kate Winslet & Leonardo DiCaprio in Titanic. Bette Davis & Joan Crawford in What Ever Happened to Baby Jane?. Vivien Leigh & Clark Cable in Gone with the Wind.
www.actressland.wordpress.com (Best Actress in a Leading Role Ranking Project)
Colin Firth & Geoffrey Rush Annette Bening & Julianne Moore Jean Dujardin & Berenice Bejo Glen Hansard & Marketa Irglova Christian Bale & Heath Ledger and for that matter... Heath Ledger & Jake Gyllenhaal
2013 Emmys FYC Amy Poehler, Jane Krakowski, Matthew Perry, Martha Plimpton, Louis CK, Nick Offerman, Adam Scott, Garret Dillahunt