As Skyline correctly points out, all motoring offences (with the exception of some parking matters, which have have now been 'de-criminalised') are criminal offences. Drink-driving is a criminal offence, as is speeding and 'causing an obstruction'. While minor matters (e.g. those dealt with by fixed penalties) don't create a 'criminal record', offences dealt with by a court (such as drink-driving) do.
Dzug correctly points out that US law only prohibits people who've been convicted of crimes of 'moral turpitude' from entry into the USA. ('Moral turpitude' includes all types of theft [even nicking a Mars bar] but not, somewhat strangely, most forms of assault. As Dzug states, it doesn't include drink-driving).
However the general rules for entering the USA are totally separate to those for entering under the Visa Waiver Program. Anyone who has ever been arrested (even if totally innocent) is ineligible to enter under the V.W.P.
So you're definitely meant to declare your drink-driving conviction, which will mean that you'll then have to go through the tedious process of applying for a visa. (It can take 6 months or more. You have to pay to apply and then pay again for a courier to return your passport. You have to apply to the police for a copy of your 'police record', and submit it to the US embassy. You also have to attend an interview in London)
Most people simply 'forget' about their convictions. The US authorities have no direct access to UK criminal records. They only know about specific individuals who're on a 'watch list' provided by the UK authorities.
Chris