Topping my list is Zooey Deschanel. I first saw her in Elf, but didn't know who she was until I saw her again in Failure to Launch. From there and through some more movies, she's become my favorite actress.
After that would come Jewel Staite. I really only know her for her roles in Firefly and Stargate Atlantis (the former of which I liked best) which portray her as 'cute'. Because of this whenever I see her in a role where she's supposed to look sexy, it never looks right. xD
Then there's Rita Wilson. I haven't actually seen anything she's been in (with exception to the Nostalgia Critic's review of Jingle All the Way), but I like how she looks. Something about the shape of her face, lol.
