Not including the veterans, I would say that the current most popular artists at TVB are the Four Fadans (not including Fala since she is no longer signed to them): Myolie Wu, Tavia Yeung, Linda Chung, and Kate Tsui and these Four Siu Sangs: Raymond Lam, Ron Ng, Bosco Wong, and Kenneth Ma. Part of what made them popular is that they were part of a golden pairing due to their on and off screen chemistry, which would make them popular for functions to bring in money for themselves and the company. Other than Kenneth and Linda (unless you count a few seconds of them together in Yes Sir, Sorry Sir), they have all been paired up together in different series.
Old pairings
I would say previous "golden" couples were:
Raymond and Linda (Heart of Greed, Moonlight Resonance)- Raymond was only a guest star in Heart of Greed but people loved the pairing so much that Raymond became one of the main stars of the sequel so that he can pair up with Linda. They were once rumored together but it's most likely not true since she seems to have been dating Phillip Ng for a number of years.
Bosco and Myolie (War of In Laws I & II)- They had great comedic chemistry with each and all the sweet moments in the series made people think they were really a couple, and they were. They dated for 7 years before breaking up.
Ron and Tavia (The Academy)- I think they only paired up once in The Academy but they would always celebrate their birthday together with their fans since it was so close together. There were never any serious rumors of them dating but their fans really liked them together.
Kenneth and Kate (La Femme Desperado, Speech of Silence)- I admit, I only put these 2 together because they are the last 2 left but they did show some nice chemistry in their series together.
New pairings
In the past 2 years, I would say that there's a shift in the popular pairings.
Ron and Myolie- They have actually been in many series together as friends, romantic partners, and even a possible mom/son situation. They can currently be seen in Triumph in the Skies 2 where they have a very sweet chemistry and will next be paired up in the grand production of Vinegar Lady in November.
Raymond and Kate- They were previously paired together in The Four but they became more popular together after Highs and Lows. They have a brother/sister relationship due to sharing the same manager and Kate is often a guest for his concerts.
Kenneth and Tavia- 2012 seemed like the year for Kenneth and Tavia since they were in 2 big series together, but most people loved them together in The Hippocratic Crush. A sequel has been filmed and will air as part of TVB's anniversary.
Bosco and Linda- Witness Security was the highest rated series in 2012 mainly due to this pairing. This is actually a spin-off of Linda's Yes Sir, Sorry Sir character and many people wanted her to finally have a happy ending. Even though this series had a tragic ending, Bosco and Linda remained a popular pairing.
What are your favorite pairings between these 2 people?