You didn't mention where you would be in Mexico. Cities have ATM's for taking money out when you need it. I advise using ATM's and taking money out for 3-4 days use. This way, you do not have a lot of cash on hand at any one time. If you are in small villages, you need cash. Pesos is the currency. Sometimes dollars would be accepted, but don't count on it. You can bring some dollars along if you wish. I would bring one dollar bills. Use them for tips. Debit cards are not accepted in some locations. Be sure to tell your bank cards that you will be using them in Mexico. Your banks could stop access if they are not informed to protect your cards for security.

what is the best currency to take to Mexico

GOING TO CANCUN IN 2 WEEKS,SHOULD I TAKE ENGLISH POUNDS,AMERICAN DOLLARS OR MEXICAN PESOS.

More info on Mexico currency - please plenty of other impartial tourist advice.

Some places take US dollars, all will accept pesos and westernized areas will take cards but don't count on cards to get you through. I reccomend getting pesos. They are the best to have anywhere you are in mexico. Don't use an airport Kiosk. Try and get them from your local bank. I pay a $15 us dollar flat rate for any amount of pesos up to $1000. have fun in mexico