What are the correct morning and evening adhkar (remembrances of Allah), and is it obligatory to recite all of them, or is it sufficient to recite some?

Morning and evening remembrances (adhkar) are the supplications and invocations from the Quran and Hadith with which a Muslim remembers his Lord. They are considered among the best acts of drawing closer to Allah. It is not obligatory to recite all the transmitted remembrances; rather, it is permissible to suffice oneself with what is easy to recite. Among the best references are "Hisn al-Muslim" by Said al-Qahtani, "Al-Adhkar" by An-Nawawi, "Al-Kalim at-Tayyib" by Ibn Taymiyyah, and "Al-Wabil as-Sayyib" by Ibn al-Qayyim.