The best women are those who attain the Paradise of delights.

The women of Paradise are of different grades, and the leaders of the women of Paradise are Khadijah, Fatimah, Maryam (Mary), and Aasiyah.

Imam Ahmad reported with an authentic chain of narration that the Prophet Muhammad (peace and blessings be upon him) drew four lines and said to the Companions,

"Do you know what these are?" They said, "Allah and His Messenger know best." He said, "The best women of the women of Paradise are Khadijah bint Khuwaylid, Fatimah bint Muhammad, Maryam bint `Imran, and Aasiyah bint Muzahim (the wife of the Pharaoh)."

Maryam and Khadijah are the best of the four. Imam Al-Bukhari narrated from `Ali ibn Abi Talib (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said,
"The best of its women is Maryam and the best of its women is Khadijah."

Maryam Bint `Imran

Maryam is the "First Lady," the best of all women.
At-Tabarani reported from Jabir that the Messenger of Allah (peace and blessings be upon him) said,

"The leaders , after Maryam bint `Imran, of the women of Paradise will be Fatimah, Khadijah, and Aasiyah the wife of the Pharaoh."

The reason why Maryam is considered to be the best of all women is clearly stated in the Qur'an,
[Behold! The angels said, "O Maryam! Allah has chosen you and purified you and preferred you above the women of all nations."] (Aal `Imran 3:42)

How could she not be the best of women when Almighty Allah has clearly stated,

[And her Lord accepted her with a goodly acceptance and made her to grow in a good manner]. (Aal `Imran 3:37)

These four women are beautiful examples of perfect, righteous women.

Maryam bint `Imran is praised by Allah in the Qur'an,

[Maryam, daughter of `Imran, whose body was chaste, so We [Allah] breathed therein something of Our Spirit. And she put faith in the words of her Lord and His scriptures, and she was of the obedient.] (At-Tahrim 66:12)

Khadijah Bint Khuwaylid

Khadijah As-Siddiqah (the true believer) believed in the Messenger (peace and blessings be upon him) without hesitation; she consoled him and supported him in every way. Her Lord gave her the good news, during her lifetime, of a palace in Paradise in which there would be no noise and no exhaustion.
Al-Bukhari reported from Abu Hurairah: "Jibreel came to the Prophet (peace and blessings be upon him) and said, 'O Messenger of Allah, Khadijah is coming to you carrying a tray of food and drink. When she comes to you, convey to her greetings of peace from her Lord and from me, and give her glad tiding of a house in Paradise in which there is neither noise nor confusion."

Aasiyah the Pharaoh's Wife

Aasiyah, the wife of the Pharaoh, despised the power and luxuries of this world and rejected the Pharaoh and his false claims of divinity, so her husband tortured her until her soul departed and returned to its Creator.

[And Allah sets forth an example for those who believe: The wife of Pharaoh when she said, "My Lord! Build for me a home with you in the Garden, and deliver me from Pharaoh and his doing, and deliver me from evil-doing folk] (At-Tahrim 66:11)

Fatimah Bint Muhammad

Fatimah Az-Zahraa', the daughter of the Prophet (peace and blessings be upon him), was patient and forbearing, and she feared Allah. She was like her father in every way, even his walk. She learned from his manners and abided by his commands.

It is reported that the Prophet (peace and blessings be upon him) said, "Fatimah is a part of me, and what hurts her hurts me" (Muslim).

She was a branch from the pure tree, brought up by the educator of humanity himself (peace and blessings be upon him).