This seems like a really fun topic... I am going to answer this in two parts... My favorite body part of mine as well as my favorite part of the opposite sex... Well my favorite body part is a tie between my eyes and my arms... I am not really sure why but they are... They are the two things that stand out the most to me when I look at myself, probably because they are the first things I look at when I look at another person as well...
When it comes to the opposite sex my favorite part of the body would have to be the boobs... Yeah I know that's what most guys would probably say but more specifically than just the boobs my fave part is the nipple... I know its strange, I prefer the word unique or different...lol... There is just something about nipples that do it for me... To me you can't truly have nice boobs with out great nipples, and yes that also includes the areola...
As soon as I can I will post pictures of my favorite body parts so stay tuned...