Sa'id bin Jubayr narrates from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that he used to pray witr with three surahs: "Glorify the name of your Lord, the Most High" [Surah al-A'la: 1], "Say: O disbelievers" [Surah al-Kafirun: 1] and "Say: He is Allah, the One" [Surah al-Ikhlas: 1].
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4858