Oddly enough, my most prized pokemon at the moment would be my Linoone. Sure, her moves aren't the greatest, and she's not even one of my main battlers, but she's saved my butt more than once in trainer battles (against the one trainer with a Milotic and against Winona are the examples I remember) by managing to defeat the opponent(s) even after my other pokemon fell. She's definitely not a pokemon I'm switching out of my team anytime soon.
Plus, Pick Up is an ability I like...it saves me from having to buy some items, heh.