Considering all the photos I've ever made, I can tell you instantly which photo was the best. But I won't, because that photo is something personal. It's the best for me because of the feelings attached to it. Technically, it's a terrible photo. There's a lot of noise, the framing is not very good, and the color balance is absolutely terrible, with a strong red haze hanging over the entire photo. But when seeing this photo I instantly remember the circumstances at the time of taking the picture, and no other photo can provoke such a strong reaction.
I guess what I'm trying to say is, photos can evoke a certain feeling inside you. Very beautiful photos can create a sensation inside of you that is incredible, but even the most beautiful photo taken by someone else cannot rival a photo that you made yourself. For me, that's what photography is all about.