Talent.
There are very few actresses who could make the character Lyla Garrity loveable. I swear, Lyla is one of the worst characters ever written - if anyone but Minka had been given the role, I'd probably want the character to be hit by a truck full of drunk football players. (Ooh! Season 3 plot idea! =D)
Plus, she's funny. That helps. =P

She has that raw talent thats just soo much better than alot of other newer actresses! She's just wonderful, and unlike alot of people I LOVE Lyla Garrity! Minka plays her well! She's just amazing and gorgeous too!