I am travelling to Canada and am wondering if i should bring US $ or EUR.?

I would think that it would be easier to exchance US money for Canadian dollars. Unless there's something I'm not aware of, Canada doesn't operate on the Euro.

We don't use Euros. Few Canadians have even seen them.

We don't use US dollars. However, Canadians often take them. Currently you will get less than a Canadian dollar per US dollar, however.

I recommend you bring Canadian dollars. This is the currency that is used in Canada and the only one that is guaranteed to be accepted. Most major banks can get you Canadian dollars fairly easily, or you can change some of your domestic currency at a bureau de change at the airport of your arrival.

Wherever you are from, it is better to use your ATM card to get Canadian dollars out as needed..you get the best exchange rate this way. Do not bring much cash.

Don't take either. Use credit cards wherever possible and obtain cash by using your ATM card. If your bank is on one of the major ATM networks, you will have no problem getting cash. Using cards gets you the commercial exchange rate which is much better than the retail rate used for exchanging cash and travelers checks. Some banks charge a 1-2% conversion fee, but that's still usually cheaper than the commissions charged by banks and money changers.