1. An individual's own viewpoint, belief, or judgment on a matter, not necessarily shared by others or based on official sources
In my personal opinion, this is the best solution.
Na minha opinião particular, esta é a melhor solução.
2. A subjective assessment or perspective that reflects personal values and experiences rather than objective fact
That's just my personal opinion, but I think the movie was excellent.
Essa é apenas a minha opinião particular, mas acho que o filme foi excelente.