Leghorns, Red Sex Links, Black Sex Links, Plymouth Rocks, and Rhode Island Reds (and "production red" crosses) are probably the best egg layers. Other good layers are Wyandottes, Orpingtons, and Australorps, among others.
I concur with Bullitt. I always say to people that as long as you are not planning on showing your birds, diversify your flock! Get a few Leghorns, a few Rhode Island Reds, Plymouth Rocks... This can be quite enjoyable to see a flock with many types of birds =)