Henry Cavill. No question.
And he's somewhat at the top of the pile in terms of prior consideration.
There is a 15-year age difference between Cavill and Craig, and what's more the latter can often appear rather older than he is. Cavill would therefore be a jarring replacement for Craig - it would look like the filmmakers were doing another first-mission reboot even though they weren't. I seriously doubt that we'll ever see Cavill as Bond. Sure, he came close once, but so did others: Sean Bean, James Brolin, Sam Neill, Sam Worthington.... prior consideration is something that hardly reserves the role of Bond for an actor to step into when he's ready. There's no line of succession.