로스트 is definitely a "One of a kind" show. i've never seen Supernatural, but if 당신 like to think and analyze problems, 로스트 is the show for you. I've watched the entire series twice, and it still amazes me. Hope this helps 당신 with your decision.
I don't even know how to try to describe Lost...there hasn't ever been a show like it. OUaT comes the closest because they're the same writers BUT it's not the same show At ALL. So, if 당신 like OUaT, there's a good chance you'll like Lost. And, in my personal opinion, 로스트 is worth watching just for Sayid ;D
수퍼내츄럴 is my 가장 좋아하는 show ever! It's about family, what real 히어로즈 look like and - gah, it's too hard for me to explain! Though, this show can be scary at times and there's blood and stuff if that bothers you.
Oh goodness, just try them out and fangirl with me XD