What are the supererogatory prayers associated with the obligatory prayers, other than the well-known twelve rak'ahs, such as four rak'ahs after Maghrib, four rak'ahs after Dhuhr, and four rak'ahs after Isha?

The supererogatory prayers other than the twelve regular Rawatib (pre- and post-Fard) are: four rak'ahs after Dhuhr, four before Asr, two before Maghrib, two after Maghrib, two before Isha, and two after Isha. The hadith about four rak'ahs after Maghrib is weak. As for four rak'ahs after Isha, it is narrated on the authority of Ibn Abbas: "The Prophet (peace and blessings of Allah be upon him) prayed Isha, then came to his house and prayed four rak'ahs..." And on the authority of Abdullah bin Amr and Aisha: "Four [rak'ahs] after Isha are equivalent to their like on Laylat al-Qadr," and its chain of narration is sound. There are no four rak'ahs after Maghrib nor four after Isha among the regular Sunan ar-Rawatib. So, whoever consistently prays twelve rak'ahs of Sunnah (four before Dhuhr, two after Dhuhr, two after Maghrib, two after Isha, and two before Fajr), Allah will build a house for him in Paradise. Whatever exceeds that is from the non-emphasized Sunan.