Happy 50th birthday to the dynamic and endlessly talented Alyson Hannigan! It's hard to believe that the adorable face from "American Pie" and the lovable Willow from "Buffy the Vampire Slayer" has hit the big 5-0. But age is just a number and we all know that you'll continue to shine and make us laugh for many more years to come. So raise a glass and cut that cake, because this is just the beginning of your fabulous 50s! Cheers to you, Alyson!