Eastern Comma, Polygonia comma
Note that the above could possibly be Question Marks, Polygonia interrogationis. The advice on differentiating the two is less helpful than it appears.
Red Admiral, Vanessa atalanta
ZRM has some pics of more exotic butterflies from warmer places.
(Mouse over pics for captions, and open them in another window for larger versions. In fact, you might even be able to see the expressions on their faces.)
UPDATE: Just for the halibut, here's a couple more.
~
