It's impossible to pick 5, so let me just throw in a couple more that seem to be absent so far.
These are current (if not older) women. So sue me. I don't know of hot chicks from 1400 BC.
Maggie Q
Eva Mendes
Rhona Mitra (might be the top of my list, honestly)
Catharine Zeta-Jones
I'm a younger guy, but I think that these are some of most attractive (famous) women in the world today. I don't think I've seen Mendes mentioned yet, nor Mitra; the latter is probably one of my all-time favorites. I've also seen Zeta-Jones mentioned only once, which is surprising.
Of course, nobody is going to argue with the likes of Grace Kelly.
It blows me away that people will make a list with Taylor Swift and not have some of these ladies on it. I mean, come on guys, Taylor seems pretty cool, but there is zero chance she's more attractive than Rhona Mitra, Zeta-Jones, etc.
For the younger crowd, Jessica Alba, Jessica Biel, and Mila Kunis have to be tops in the under-30 (shit, are they all under 30?) crowd. I guess Megan Fox is probably on this list as well, no question she's hot, but I have trouble getting as excited about her as I do the aforementioned.