Craig was perfect in CR, perfect enough that I really can't imagine anyone else in that role.
As for the following films? I think Ralph Fiennes would've been good as Bond – which, given his role in Skyfall and Spectre, makes me think the producers felt the same. Obvious in hindsight, but Idris Elba would've been a great choice.
As I recall, Clive Owen was the favorite at the time. Although I'm sure he would've made a fine Bond, I think the producers had the right idea in casting Craig; breaking the mold and moving Bond beyond the boundaries of Sean Connery's vague likeness.
What kind of monster asks me to replace the lead from one of my favorite films of all time?
Present-day Dan Stevens, or Clive Owen. Would be curious to see a Hugh Jackman version too.
I don't see his name get tossed around enough for post-Craig Bond. Hiddleston might be alright, but I was not convinced by The Night Manager. Stevens' turn in The Guest was a much better audition for Bond, I think.