For my Portuguese Egg tart fix, I come here to Market 168/168 Market. I usually buy a few and put it in the fridge. before i eat them, I would warm it up for about 10 seconds in the microwave then into the convenent oven for about 5 minutes it goes. Now I don't know how it stand up to one you might get in SF or China Town in NY but I am pretty satified with the taste. The Crust is flaky and not soggy at the center. The filling doesn't smell like egg (The custard usually shouldn't smell like eggs...) Their other pastries are pretty tasty and very cheap as well. I usually grab a few of the cheese puff Milk butter bun and croissant hot dogs.
Overall, great place. Their hot deli is good too. You could grab 3 item dim sum/pastry for $1.88. Way cool.
I drive for miles once a week to grab this stuff. :)