1. the one with the guy breaking though a wall of snow. when i use it, i feel like i'm on the alps, about to score a hot chick, i feel all sporty and manly.
2. or the one that does the brushing for me because i'm lazy
3. or the one that kills all bacteria because the advertising told me that all bacteria must be feared and killed.
4. or the one that costs the price of a small african nation's gdp because some dentist is getting a kickback
not really. i just use plain old colgate. that said, i've been enjoying a decent electric toothbrush. luckily i got it for free from a friend.