I was selfish and picked the most outgoing, confident one, the one they'd have no trouble finding a home for. They told me about some of the other ones that had been there a long time and really needed a home, but we were taking ONE cat home, one to play with our son and get along in a small apartment with small gardens and other cats outside, and a shy or traumatized cat would not be happy in our surroundings and family.
It's still one cat less in the shelter. If we could have more I would happily take the more "difficult" cats, but my dh refuses to have more than one cat and I have to respect that. So this is our one family cat.
Hey, if it was up to me I'd probably turn into one of those cat ladies who lives in the woods with a zillion cats all over the place 
Try asking your mother if she wants a friendly cat, or can tolerate a shy, aloof or independent one. What about a nervous cat that will easily bite or claw? The most "deserving" cats in the shelter we visited were either quite aggressive, or apathetic and very quiet
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/Selle Italia SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Terry Falcon X
2000 Schwinn Fastback Comp road bike/Specialized Jett