For me, the criteria i first judge girls on is their dressing
style. Usually, if they dress well and are hip, i would find them
pretty even though their looks are actually so-so.
That is only the 1st impression, but it is important too...it would
make me want to know a girl more as a person or not. If i want to
know her more but am not attracted to her in a manner of a r/s, i
might slowly start to like her due to her character and attitude to
life.
I would look for someone who i can share my life and problems with
and not an immature girl that just wants to play, play and play. If
there are 2 girls, 1 who is above average looking and 1 who is
super pretty and both dress well (that is a must for me!), if i
figure i could talk to the average girl more and open up and share
life together, then she would be the one. 
Those guys who ditch you after they see what you look like, it
might be because of your looks or they are guys who are just after
flesh and you don't meet their criteria. You might want to try to
improve your dressing style first as i can assure it would make
guys take a 2nd glance... 
Wish you well! 
