Search Global Financial Data. It has daily and monthly exchange rates for many countries, going back hundreds of years in some cases.

• Select GFDatabase and look in the Series Type for Exchange Rates.

Federal Reserve Statistical Release: Foreign Exchange Rates (H.10) has exchange rates for 23 countries against the US Dollar.

Use Bloomberg, available in the Business Library and the Finance Lab

• Hit the yellow <CURRENCY> key and then the green <GO> key.
• For the best and worst performing currencies relative to a selected currency, type WCRS and hit <GO>.

For historical annual exchange rates for 40+ currencies compared to the USD go to the freely available MeasuringWorth.com