The sunrise at Pico do Arieiro is undoubtedly the most popular and spectacular spot to experience this natural phenomenon. Keep in mind that it can get crowded, so make sure to arrive early to secure a parking spot and find a place to sit or stand.
There are several viewpoints at Pico do Arieiro where you can admire the sunrise, so you have options. Personally, I would recommend choosing another spot if one is too crowded.
Enjoy!