These always sneak up on me.
Shiri Appleby (but I think she's even more adorable in her ER doctor outfit, complete with glasses).
All of the main women in Bones (L to R: Michaela Conlin, Emily Deschanel & Tamara Taylor).
Morena Baccarin from Firefly. (Doesn't she look like our own Tippler?)
Tina Fey
I also appreciate Amy Poehler and Reese Witherspoon, but I can't seem to find pictures that capture what I like about them. The ones that disturb me a little are Jennifer Connelly and Meg Ryan.
In a way, this is very complex subject that I wish I had more time to get into. Suffice it to say that these are all women I find attractive in a way that makes me go, "she's pretty" and simultaneously want to give them a hug.