Canadianbitcoins.com
I've done a bunch of transactions with them. The main guy, James, is a friendly, helpful dude. It ain't instant, but it's pretty good. If you do direct bank deposit, you generally get your bitcoins pretty fast. They've got an actual storefront address, a contact #, contact emails, and they actually respond in reasonable time.
For example. I put a buy order in on a saturday morning, got an email with my deposit amount and an RBC account#, deposited around 10am, texted james that the drop had been made, coins were in my wallet by noon. That's probably a best-case-scenario, but even when it was a bank transfer, i got my coins the next day as soon as they verified the transfer into their account. I dunno how many people canadianbitcoins has handling transactions, so sometimes it'll be a next day thing simply because the guy doing the transaction processing has to sleep sometime, ya know?
Basically, i'm sayin' they're a reliable, friendly exchange with excellent customer service.
and no, they didn't pay me to say that!