I would say the best all around athletes are from the NFL. If we're talking a combination of what makes a great athlete. Speed, strength, endurance, agility, etc.
Depends on whether your definition of athlete includes "good at sports", "good at one sport" or neither. People often refer to Peyton Manning as an unathletic QB, but that's all depending on your definition. He's as good at his athletic area of expertise as anyone in the world, so in that sense he is extremely athletic. Another person might consider an uncoordinated buffoon that sucks at sports a good athlete because he is fast and strong. Novak is as good at his sport right now as anyone else is at theirs. He's also in good shape and is quite agile. I'd be interested in kidb defining his terms of athleticism more specifically.
I tend to agree, though i might give the edge to Lebron. This is a hard question because it's hard to know exactly what the OP means by "athlete."
Yeah, but I'm betting there are done NFLers and boxers that could go nuts in UFC if given the proper training.
That's hard. Look at guys like Ndamukong Suh or Joe Thomas. That's a combination of size, speed and strength that about .000000000000001% of the population have. Does that make them the best?