Coca-cola and Pepsi have never loved each other. If you look at the youtube links below, you can see how they go for each other quite directly in adverts from the 1980s. No one seems to explicitly mention competitors in adverts today, but check out the videos and links about "New Coke":
http://www.youtube.com/watch?v=5vw2g5zR9PY
http://www.youtube.com/watch?v=qfhFBTL-Xsw
http://www.youtube.com/watch?v=8_hvOBnsirI&feature=related
http://www.youtube.com/watch?v=mB2WW7q0ghw&feature=related
