Gene Hackman was the first, so I have some affection for my childhood Lex. Keving Spacey was pretty much doing a homage to that Lex for Superman Returns.
Michael Rosenbaum did bring some complexity to the role for Smallville.
I actually didn't hate on the casting of Jesse Eisenberg or making Lex into a young genius. But he did play him too unhinged. It only makes sense for him to act so mad after he gets exposed to the Kryptonian archives and gets access to cosmic data and threats no human has ever seen.