If you like Har Mar Superstar, Amy Sedaris, Tim and Eric, Tracy Ullman or Jean Teasedale, I feel pretty confident you will thoroughly enjoy Leslie Hall.
I've followed her online for a few years, and have been impressed by the traveling Gem Sweater Museum, her guest appearance on Yo Gabba Gabba, and the plethora of entertaining videos. But seeing her live sealed the deal for me. She owned it - there's a sincerity behind the gimmick that makes it work. Plus, she eptomizes my favorite comedic archetype - the unnattractive character with grandiose delusions (Will Farrell, Danny McBride, Amy Sedaris).
Check out more at her site and wikipedia entry.