Hello Daai!
Yadech have had 3 together lakorns so far.
Duang Jai Akkanee was their first lakorn and it was one amongst 4 parts of a series during 2010. The ratings were average but of all the couples in that series, Yadech were no doubt the most popular and were in high demand after that. Their second is Game Rai Game Rak. This lakorn aired during the time where Bangkok was facing problems with flooding so that impacted the ratings. However they were the talk of the town during that time and they captured the hearts of many people, both viewers and actors within the entertainment industry. Their third lakorn is a remake called Toranee Nee Ni Krai Krong. The ratings were decent but the overall feedback wasn't as strong compared to the other two. Generally, their works have done well. They might not have brought in the highest ratings for Channel 3 but they were able to make a name for themselves and create huge tidings. They are the "it" couple of this generation and they've maintained this title for 4 years now.
As for their individual works, Nadech debuted with Ngao Rak Luang Jai. From what I remember, the ratings were decent and many people immediately took interest in Nadech afterwards. He even won Best Rising Actor for one award show even though he wasn't the main lead in there. His other lakorn with Kimberley, Raeng Pradtana did quite well in terms of ratings but it kinda had mixed feedback. Some people thought that Nadech and Kim don't look compatible and don't have chemistry whereas other people liked them. The krasae wasn't as strong as any Yadech lakorn. His latest movie called Koo Gum didn't do well for a few reasons. One, the main actress Richie never had any acting experience before. She was casted because her manager (Richie and Nadech share the same manager) consulted with the production and told them that they can only get Nadech if they agree to cast one of his kids as the lead girl. Technically, she was part of a package deal. The production didn't agree at first but eventually gave in because they really wanted Nadech for the movie. Many people agree that Richie isn't suitable for her role and she's a very stiff and emotionless actress. Another reason why it didn't do too well was because of the way it was directed. I should also mention that the infamous Pee Mak Phra Kanong was airing at the same time. Even though Koo Gum wasn't considered a success, many have praised Nadech for his suitability as Kobori.
On the other hand, Yaya debuted in a lakorn called Kularb Rai Narm. She did another lakorn and sitcom before this but the lakorn was never broadcasted for an unknown reason. The ratings were decent but I should mention that a lot of attention was on Ploy instead because even though she's the nang rai (antagonist), she's pretty much considered as the main character because the story revolves around her. The title of the lakorn refers to her character too. What's interesting is that a very talented senior actress, Benz Pornchita saw Yaya on screen for the very first time and called the producer of Kularb Rai Nam, P'Pin and told her, "This young girl will definitely become popular". Sure enough, Benz was so right. It was Duang Jai Akkanee that brought Yaya to stardom and many magazines have labelled her as the new princess of the industry. So many people were amazed at how she was able to portray Jeed so well since this character is a big contrast to her role in Kularb Rai Nam. Later on, she acted in Tawan Deurd with Mark Prin. The feedback was quite okay and it did extremely well with ratings. It got 16 on the ending episode which is Yaya's best thus far. At one point, Mark's fans were fighting with Nadech's fans because they wanted Yaya as Mark's koo kwan. haha. Maya Tawan and Dao Reung are Yaya's latest works and both did okay. Dao Reung started very well in the beginning but the ratings dropped half way and then went up. Maya Tawan started a little weak but it worked it's way up and at the end, got a double digit for the last episode. An important note to make is that both of these lakorns are remakes and Dao Reung was quite loved by the rural population.
I hope this helps you.
Yadech have had 3 together lakorns so far.
Duang Jai Akkanee was their first lakorn and it was one amongst 4 parts of a series during 2010. The ratings were average but of all the couples in that series, Yadech were no doubt the most popular and were in high demand after that. Their second is Game Rai Game Rak. This lakorn aired during the time where Bangkok was facing problems with flooding so that impacted the ratings. However they were the talk of the town during that time and they captured the hearts of many people, both viewers and actors within the entertainment industry. Their third lakorn is a remake called Toranee Nee Ni Krai Krong. The ratings were decent but the overall feedback wasn't as strong compared to the other two. Generally, their works have done well. They might not have brought in the highest ratings for Channel 3 but they were able to make a name for themselves and create huge tidings. They are the "it" couple of this generation and they've maintained this title for 4 years now.
As for their individual works, Nadech debuted with Ngao Rak Luang Jai. From what I remember, the ratings were decent and many people immediately took interest in Nadech afterwards. He even won Best Rising Actor for one award show even though he wasn't the main lead in there. His other lakorn with Kimberley, Raeng Pradtana did quite well in terms of ratings but it kinda had mixed feedback. Some people thought that Nadech and Kim don't look compatible and don't have chemistry whereas other people liked them. The krasae wasn't as strong as any Yadech lakorn. His latest movie called Koo Gum didn't do well for a few reasons. One, the main actress Richie never had any acting experience before. She was casted because her manager (Richie and Nadech share the same manager) consulted with the production and told them that they can only get Nadech if they agree to cast one of his kids as the lead girl. Technically, she was part of a package deal. The production didn't agree at first but eventually gave in because they really wanted Nadech for the movie. Many people agree that Richie isn't suitable for her role and she's a very stiff and emotionless actress. Another reason why it didn't do too well was because of the way it was directed. I should also mention that the infamous Pee Mak Phra Kanong was airing at the same time. Even though Koo Gum wasn't considered a success, many have praised Nadech for his suitability as Kobori.
On the other hand, Yaya debuted in a lakorn called Kularb Rai Narm. She did another lakorn and sitcom before this but the lakorn was never broadcasted for an unknown reason. The ratings were decent but I should mention that a lot of attention was on Ploy instead because even though she's the nang rai (antagonist), she's pretty much considered as the main character because the story revolves around her. The title of the lakorn refers to her character too. What's interesting is that a very talented senior actress, Benz Pornchita saw Yaya on screen for the very first time and called the producer of Kularb Rai Nam, P'Pin and told her, "This young girl will definitely become popular". Sure enough, Benz was so right. It was Duang Jai Akkanee that brought Yaya to stardom and many magazines have labelled her as the new princess of the industry. So many people were amazed at how she was able to portray Jeed so well since this character is a big contrast to her role in Kularb Rai Nam. Later on, she acted in Tawan Deurd with Mark Prin. The feedback was quite okay and it did extremely well with ratings. It got 16 on the ending episode which is Yaya's best thus far. At one point, Mark's fans were fighting with Nadech's fans because they wanted Yaya as Mark's koo kwan. haha. Maya Tawan and Dao Reung are Yaya's latest works and both did okay. Dao Reung started very well in the beginning but the ratings dropped half way and then went up. Maya Tawan started a little weak but it worked it's way up and at the end, got a double digit for the last episode. An important note to make is that both of these lakorns are remakes and Dao Reung was quite loved by the rural population.
I hope this helps you.
I just wanted to help out and be as thorough as possible. Since I shared insights on Yadech's works, I thought it'd be appropriate to share some thoughts on Yaya from different people in the industry too. I'm someone who likes reading interviews and sometimes I'd translate them into English for future reference. Hope you all don't mind. I'm sharing this because I find that most of these people say similar things about Yaya. 
