I will watch any movie that stars Lee Byung Hun because he is the most handsome Korean actor, and he does actually have genuine acting ability. However, this was a movie in which he wasn't really allowed to reveal his range of acting skills, and is largely a disposable movie which will probably be long forgotten in years to come.
This movie essentially fits in to the current Korean fad for 'romantic comedies' with added inspiration from the U.S. series Sex and The City. (In fact, I couldn't really see why this movie wasn't just made as a TV production rather than wasting good money as a movie format.) The lead actor played by Lee Byung Hun plays around with 3 sisters of very differing personalities. We get to see him pair up again with the actress Choi Ji Woo, who plays one of the sisters. Previously, Lee Byung Hun had starred in the highly successful TV drama series Beautiful Days with Choi Ji Woo. In that drama series, Choi Ji Woo played a very quiet, ailing, angelic figure. It was therefore quite surprising to see her play a comic role in Everybody Has A Secret so well. As a result, I thought Choi Ji Woo's character was the strongest in the whole movie, and not only that, but even perhaps the ONLY personality in the movie. Everyone else was a rather two-dimensional cut out figure. I felt I couldn't really care about the fate of any of them overall. In fact, by the end, no character has achieved anything worthy of note. I couldn't even possibly remember any of the character's names, too. That says a lot for the impact of the film.
I think this is only a movie for die-hard Lee Byung Hun fans or for someone who desperately needs to get through a rainy afternoon. It's purely an excuse to ogle at him for an hour or two. It's not a movie about acting standards. Anyone who knows Lee Byung Hun's reputation amongst Koreans as a 'player' will start to wonder how much they see on screen might ironically be some reflection of Lee Byung Hun's real life. That was the only thought that remained with me after the movie finished.