I am a pretty tall, broadly built man, so obv I'm a little biased because I'm reasonably confident that I could kill another man if it came to it. However, the concept of this question bothers me, because it doesn't indicate what kind of bear. Trust me, if you ever come face to face with a fully grown grizzly, you'd prefer the man. Monsters are real, and they can destroy you on accident, while men have weak necks and unprotected kidneys.

If I was dead either way though, obv I'd rather it be an emotionless grizzly who'd tear me apart pretty quickly.