No contest - Pantene. At least they USED to have the best commercials. Seems like their commercials have steadily become less and less erotic over the past couple of years (believe me, I've followed them closely!). At least that's the case for the domestic (USA) market.

I would say that the best commercials now are those produced overseas (speaking from America). In particular, the commercials from Asia (China, Thailand, Vietnam, Philippines, Malaysia, etc.) show some really stunning hair. Pantene, Rejoice, Sunsilk and others. A quick search on u-toob will reveal many dozens of stunning Asian hair commercials. Unfortunately, they're brief and low-resolution. I sure wish I could get the original, full-resolution (broadcast/cable TV quality) versions of these. Sigh...