I just saw an interesting TV spot for MetLife which is made solely of letters, mostly animation of hand-drawn "IF" --
This link takes you to the main "IF" page. Play with the mouse-overs on various "ifs".
Then click the "Watch T.V." link in the upper right corner to watch the TV spot.
Trying to find out who actually did the creative on the spot, but the New York Times credits both Foote Cone (business-to-business) and Y&R Advertising in New York (consumer) as MetLife's agencies.