Not sure about YVR, but I always use Alamo at LAX and their service is always excellent. It's incredibly efficient - assuming you've already booked online you walk into the lot, pick a car, show the security guard your drivers license and rental agreement, and drive away. Coming back you just drive in, give them the keys and get on the shuttle for your flight. I've never been dinged with any dubious charges afterwards. Price is always incredibly cheap, and if you are a COPA or AOPA member you'll get a discount. And as others have said, don't bother with CDW as long as you have it on your credit card or auto insurance.