Probably the most decent place for macarons in Markham. It's a small shop but the ambiance is aighhht for relaxation and conversation. The Earl Grey and Lychee Rose are the BEST flavours there. Everything from its size, flavour, colour, presentation, and even sandwich ratio was perfect (compared to other Markham shops). The prices vary by flavour but each piece can run from $2.25-$2.50 (no tax on half dozen). So if you can't afford to fly to Paris or New York or you're too lazy to drive down to Nadege, take my advice and visit Ruelo. This place serves cakes, coffee, and high tea as well if you're craving something different. The coffee isn't the greatest but when you pair it with something as delectable as the pistachio macaron, you won't even notice.
EDIT - Jun 14/11 - I finally had the chance to try the Wasabi Grapefruit macaron. They never seemed to have it when I go, but this time I was lucky enough to grab one. I was skeptical at first about the combination of japanese mustard with the bitter grapefruit, but it works! Definitely go try!