BOTTOM LINE: Best FOREX rates in downtown (only 100 basis points over the daily rate) - don't get grifted by your bank!
Located just beneath the condos of 25 Carlton, I've been going to these guys to exchange CAD to USD and EUR for years since I discovered how cheap their rates are. They also allow you to pay with your debit card, but you're limited (obviously) by your daily limit. As usual, always do your due diligence - especially for other currencies - but I've never found lower rates anywhere else. Ever. And I consider myself to be extremely frugal.
If you're Joe Blow walking off the streets, most banks (in my experience) will ding you for approximately 300 basis points (aka 3% higher than the day's going rate, which, sadly, is still better than what your credit card company will charge you). If you're exchanging higher amounts (i.e., over $1,000) you'll often receive a preferential rate, which can be further lowered if you have a "preferred" account with them, but even then you're still gonna get dinged approximately 200 basis points. And trust me, no amount of (attempted) charming or flirting will get you anywhere. :P
The College Currency guys, though, are like "BAM - we'll only charge you 100 basis points, flat rate - show me the money!". So whether you're Joe Blow or Joe Millionaire, you get more for your money here. Don't be a sucker for the banks. Go to these guys and treat yourself to a beer for getting the lowest rate possible. :)