Possibly the last ever good show that TCS/Mediacorp would do. Its stellar cast and its theme of babies that were switched at birth (one of the most popular themes in the genre) make for the perfect telenovela/teleserye. Zoe and Fann are tops as the eponymous babies switched at birth, while Li Nan Xing does one of his best roles as the comical "Ah Da" who cannot gamble for nuts. And Tay Ping Hui's "professional thief" persona make him the legit successor to Law Kar Leung.
Fun fact: The Ultimatum was (and still is) so popular in the US that it inspired a similar telenovela, Switched At Birth, which debuted in 2011 and aired for five seasons on the ABC channel for a total of 103 episodes.
After The Ultimatum ended its run, sadly Mediacorp would turn into the Mediacorpse that it is today, and all of its subsequent shows would become complete wastes of money and time. There will likely never be another show like The Ultimatum again. For that reason, I give The Ultimatum 10 stars.