When one sees something that one likes, he should recite:
اَلْحَمْدُ لِلّٰهِ الَّذِي بِنِعْمَتِهِ تَتِمُّ الصَّالِحَاتُ
All praise is due to Allah Ta‘ala, the One through Whose favour all good takes place.
When one sees something that one does not like, he should recite:
الْحَمْدُ لِلّٰهِ عَلَى كُلِّ حَالٍ
All praise is due to Allah Ta‘ala in all conditions.
عن عائشة رضي الله عنها قالت: كان رسول الله صلى الله عليه وسلم إذا رأى ما يحب قال: الحمد لله الذي بنعمته تتم الصالحات وإذا رأى ما يكره قال: الحمد لله على كل حال (عمل اليوم والليلة لابن السني، الرقم: 378)
Hazrat Aaishah (radhiyallahu ‘anha) reports that when Rasulullah (sallallahu ‘alaihi wasallam) would see something that he liked, he would recite اَلْحَمْدُ لِلّٰهِ الَّذِي بِنِعْمَتِهِ تَتِمُّ الصَّالِحَاتُ, and when he would see something that he disliked, he would recite الْحَمْدُ لِلّٰهِ عَلَى كُلِّ حَالٍ.