It is well-known among Muslims that the best wife of the Prophet (PBUH&HF) was Khadija (RA). She was the first woman who embraced Islam and spent all her wealth for the cause of Allah and the Prophet never married another woman as long as Khadija was alive.
The Messenger of Allah gave the name of the best women of the world in chronological order and one should not be surprised that the name of Aisha is missing:
The Messenger of Allah (PBUH&HF) said: "The most excellent of the women of all worlds whom Allah chose over all women are: Asiya the wife of Pharaoh, Mary the daughter of Imran, Khadija the daughter of Khuwaylid, and Fatimah the daughter of Muhammad."
Sunni references:
1.Sahih al-Tirmidhi, v5, p702
2.al-Mustadrak, by al-Hakim, v3, p157, who said this tradition is authentic based on the criteria of two Shaikhs (al-Bukhari and Muslim)
3. Musnad Ahmad Ibn Hanbal, v3, p135
4. Fadha'il al-Sahaba, by Ahmad Ibn Hanbal, v2, p755, Tradition #1325
5.Hilyatul Awliyaa, by Abu Nu'aym, v2, p344
Furthermore, Ibn Abbas (RA) narrated:
The Messenger of Allah (PBUH&HF) said: Four women are the mistress of the worlds: Mary, Asiya (the wife of Pharaoh), Khadija, and Fatimah. And the most excellent one among them in the world is Fatimah."
Sunni references:
Ibn Asakir, as quoted in Tafsir al-Durr al-Manthoor
Moreover, after the demise of Khadija (RA) when the Prophet (PBUH&HF) married Aisha and others, he explicitly preferred some of them over Aisha and said they are better than Aisha (see Sahih al- Tirmidhi; al-Isti'ab by Ibn Abd al-Barr; and al-Isabah, by Ibn Hajar al-Asqalani, in the biography of Safiyya).
Also the verse: "Perhaps if he divorces you, his Lord will give him wives who are better than you, who submit and believe (Quran 66:5)" clearly indicates that there were believing women among the Muslims who were much better than Aisha.
Envy so controlled her heart and her mind that she conducted herself in the presence of the Messenger of Allah (PBUH&HF) without respect or manners. On one occasion, Aisha said to the Prophet (PBUH&HF), when he mentioned Khadija in her presence:
Sahih Bukhari Hadith: 5.168.b
... Narrated Aisha: Once Hala Bint Khuwailid, Khadija's sister, asked the permission of the Prophet to enter. On that, the Prophet remembered the way Khadija used to ask permission, and that made him sad. He said, "O Allah! Hala!" So I became jealous and said, "What makes you remember an old woman amongst the old women of Quraish an old woman (with a teethless mouth) of red gums who died long ago, and in whose place Allah has given you somebody better than her?"
The Prophet of Allah (PBUH&HF) became very angry at this until his hair stood. (also reported in Muslim)