Physically:

• Shorter stature (5'6″ and less)
• Long hair, especially wavy hair
• Reasonably good shape ( few pounds extra is fine, obese is a turn off)

Mentally:

• Intelligence
• Positivity
• Honesty

Now let's describe a bit more in detail

Short stature - I've always found shorter girls cuter, as if they're more precious and more in need of my protection. This is not a hard rule though, I dated tall girls

Long hair - A particularly strange attraction of mine, the longer the hair girl has, the more attractive she seems to me. Bald women creep me out

Good shape - sure, not everyone wants to spend seven days a week in the gym, but heavily overweight is a sign of unhealthy lifestyle

Intelligence - if the conversation is mostly shallow small talk about whose friend did what with whom. Someone who can challenge my points of view is a welcome guest

Positivity - often these days I see people upset, depressed, offended over the silliest of things. A positive girl is like a sunshine after a rainy day, makes every problem seem less serious and easier to overcome

Honesty - we've all been there. We've all dredded that sentence spelling an impending doom. The calm before the storm. The all powerful “I'm fine, nothing's wrong”. I will rather take an painful truth than a sweet lie.

Exceptions apply, I'll take redheads and Latinas in any shape and form :D