That’s a really difficult one. The book Bond is a snob in a way that doesn’t really translate to the later culture in which so many of the films are set. Plus, I stopped watching the movies after Quantum of Solace - and had only been slightly interested from around Licence to Kill onwards, until Casino Royale.
If I had to say then perhaps a mix of Craig in Casino and Connery in the very early ones. Book Bond was a bit rough around the edges and definitely not dropping ‘witty’ one-liners all the time.