Honorable mentions: knot socks, Chapstick, Crest/Colgate, Pantene, (even though I kind of love Klorane), Nair, 5 blade razors, American Apparel thigh highs, and pretty much all electronics (I have yet to find $1 headphones and $250 laptops like at home), and of course that includes iProducts. Apple's European prices are not the one. The French price is cray cray. $300 versus €679? Yeah, non merci.
Thankfully there's always Blighty. Phew! Most American products can be found in England so if you don't mind shipping, or Eurostaring it every once and again, you're not completely out of luck. Sometimes it's reassuring knowing London's just a hop, skip and a jump away.