On the question of my opinion of boobs, my first reaction was; I care about them too much, probably spend too much time staring at them and wish I could get over them.
Then I though about three girls who I consider most attractive in my circle of friends at uni:
1 (Now my best friend) I don't think I noticed the size of her rack until after I had asked her out and been rejected by her, and then it was kinda hard not to as she was wearing not the most concealing bikini top.
2, (Girl I'm planning on asking out) I met this girl and chatted with her a bit, we made each other laugh, but I barely had a chance to notice more than the fact that she was really kinda cute, it wasn't until about the third time I met her that I realised 'woah, she has huge tits. bonus'.
3, (girl I share a few classes with)...I honestly don't know how well set she is, her face is that beautiful.
So maybe I'm not as shallow as I first thought.
As far as what I do generally find sexy.... pretty much anything different from the surroundings, for example the other day a girl walked past me at uni wearing very short shorts and a top tied up really high and I needed to have my tongue put back in my head, but if I saw a girl dressed that way at the beach I wouldn't look twice.