The only bad restaurant experience we had in Taipei was at a Japanese restaurant, Sasa Sushi (笹鮨). There is a lot of Japanese influence on Taiwanese culture as Taiwan was occupied by Japan for multiple decades. A local friend recommended us to try Sushi Omakase in Taipei. It's supposed to be really good at a fraction of the typical costs.
We must have picked the wrong place. Usually, Sushi rice is supposed to bring out and complement the flavor in fish. However at Sasa Sushi, the vinegar taste in the rice at Sasa Sushi overpowered everything else. At one point, we asked nicely if we could stick with the white rice instead of their special-made dark rice which had an even stronger vinegar taste. The chef was so offended by that request that he tried to ridicule us by asking if we had real omakase before. He insinuated that California rolls, an American take on Japanese sushi, didn't count as real Sushi and shouldn't be compared with his creations.
The bill came out to close to $500 for the two of us which was surprising - that was similar to what we would pay for a good Omakase in New York City! Maybe the menu was more expensive than usual because we went on New Year's Eve but we didn't think it would even be worth it at half of what we paid.