What to do when a guy is head over heels for you and you don't feel the same?

So this guy around my age moved into the house across the street and we started chatting and eventually hung out. One night we drank too much and he spent the night and I'm sure you can put the pieces together. I thought I was really into him but after hanging out for a few days and actually getting to know him and how his personality is, I realized we weren't right for each other. I don't see myself dating him and don't want to lead him on while not breaking his heart. How should I handle this?