I absolutely adore the Grant/Hepburn partnerships (well, maybe not so much Sylvia Scarlett).
I thought that they complimented each other well and wish they had made more films together. They definitely had onscreen magic that I think has yet to be topped. Hepburn proved to be the strongest of all the leading ladies who could forgive Grant's characters who were often flawed but irresistibly charming without coming off like a sap. Hepburn was also a notorious scene stealer and I assume that kept Grant on his toes and made for some of their best roles throughout their careers. Bringing Up Baby is my favorite of their collaborations.
Grant on Hepburn: "She was this slip of a women and I never liked skinny women. But she had this thing, this air you might call it, the most totally magnetic women I'd ever seen, and probably ever seen since. You had to look at her, you had to listen to her, there was no escaping her."
Sylvia Scarlett (1935)
Bringing Up Baby (1938)
The Philadelphia Story (1940)
Love these two together!