5) Kaley Cuoco, Big Bang Theory
She would have even ranked higher, but in my opinion her character/or even the actress itself lost a bit of the good ol hottieness from Season 1.
4) Katrina Bowden, 30 Rock
Katrina is the definition of hotness. If you ever need to imagine how Barbie would look as a real time actor - its probably like Katrina Bowden. Her character on 30 Rock ( I honestly don't even know what -exactly- her job is) appears from time to time as a part-time secretary of Liz Lemon.
The writing geeks on 30 Rock are lusting for her - and so do we. By the way, you can currently see her in Tucker and Dale vs Evil.
3) Olivia Wilde, House
You could previously see her as Mischa Bartons lesbian girlfriend on OC.California.
2) Christina Hendricks, Mad Men
Diora Baird, except Diora is not on TV because she is pretty busy shooting shi***y movies.
Last pics i've seen of Christina are not so much hotness though, since she is taking this whole "curves thingy" a little too serious. I hope she gets back in shape for another season of Mad Men - if there is one.
1) Blake Lively, Gossip Girl
I've probably missed some other great actresses on here and as always, these lists are kind of a matter of opinion so feel free to comment about your Top-5 choices.
All pictures belong to their rightful owners/the producers/the actress herself.