If you want to see penguins, you should add Punta Tombo to your list. Punta Tombo is the home to thousands of Magelan penguins. However, the penguins are not there all year round. You should visit Punta Tombo between October and February. In September the penguins start to arrive in Punta Tombo. Between March and April they are leaving the area. The chicks are born in December and then leave the nest in January. So that is the best time to see fluffy pingus.
Punta Tombo is located south of Trelew and should be combined with a visit to Peninsula Valdes. The nearest airports are in Trelew and Puerto Madryn. You can visit it with a tour or you take a rental car and drive yourself. The rental car has the advantage, that you can decide yourself how long you want to stay with the penguins. If you have a flight from Trelew, it is best to go directly from there because it is the nearest town. Trelew itself you can skip.
The road is gravel for the last 20km, otherwise the way is paved with long and straight roads. Once you arrive at Punta Tombo you have to go to the ticket office. The price is quite cheap and was less than 10$ in Jan 2020.
There is a nice visitor center where you can see what other types of penguins are on earth. Then you go back to your car with the ticket and drive down the street again for 1km. Your ticket will be checked here and you can start walking along a path between the penguins. You can really see a lot of pigunins and also very close to the path. Sometimes they just run on the trail in front of you. At the end of the path you come to two viewpoints, from which you can look at the coast. Here you can see the penguins swimming.
The path is one-way. If you have seen enough penguins at some point, you can take the same route back to the start, where you will also find a simple restaurant. You should plan one day for Punta Tombo.