There are a few that are good and a few that are not-so-good (and those not-so-good ones will remain nameless, as per forum rules).
I've never bought a car off a dealer, but I've met and spent a fair bit of time dealing with the guys from Top Secret Imports as well as the guys from JapLink, and would recommend both places.
It really depends on who you're comfortable dealing with, who you think is being genuine (and not just being nice to you in order to get a sale out of you), and what budget you've got to deal with. Some people have good experiences with certain dealers, some don't. This is why you should read this thread...