Right at the moment there is a girl to whom I am tremendously attracted. It's actually been her idea for us not to get any closer, because (her words) "I don't want to end up being the reason you don't get what you want from life."
She's amazing, and I wish I could find a way to work her plans for her life and my plans for mine together, but she's very close to her family and (again, her words) could never settle down more than an hour's drive from her dad, much less raise kids where she couldn't bring them to see Grandpa on a regular basis (total daddy's girl). Meanwhile, it would be career suicide for me to move where she is (rural southeastern Ohio, not much call for accountants 'round those parts.) I've got my heart set on Boston (where I grew up), maybe Philadelphia since I've got family in Delaware m'self.
I really do wish I could find a way to make it work. She's attractive. She brings out the best in me. I like the person I become when I talk to her. She lights up my life...but we may just be too star-crossed to make it "serious".
(edit: And since religion's come up in so many of these posts, for what it's worth she's Wiccan and I'm classical Roman, but we're both pagans.)