top 5 costars who have magic on and offscreen (these are in no particular order)

David Tennant & Billie Piper (Doctor Who) “..she giggles at a shot of Tennant standing with thighs manfully thrust apart: “Check it out!” she purrs, “Sexual!” 
Time for another take. When it’s finished, Billie and David spontaneously burst into a comedy hoofing – half tapdancing, half dad-dancing. […] There’s no doubt that these two get on like a house on fire.”