Macarons.

If you ever visit Paris, these are the best macarons I've ever had. A co-worker brought them into the office after his trip there.

Laduree

If you find yourself in Toronto instead, check out Ruelo Patisserie for super yummy macarons. 

In Taipei, I have not had a decent macaron. Though there are plenty of macaron shops, they all turn out to be sugary gel sandwiches. One reason for this might be because of the Taiwanese macaron, a traditional dessert which looks practically identical to it's French cousin, but however, is a completely different thing altogether. Perhaps this affects how the Taiwanese consumer expects the taste and texture of the French macaron to be. 

Anyhow, since macarons are expensive in any part of the world, I recommend staying away from macarons in Taipei, unless they are of the Taiwanese variety.

On a bizarre side note, I saw Uniqlo selling Laduree T-Shirts. I guess if you can't make it to Paris, and can't get any decent macrons in Taipei, you can still wear a Laduree macaron.