Narrated Ibn Umar (may Allaah be pleased with them both).
He (the Prophet – may Allah bless him and grant him peace ) said:
“The best prayer with Allaah is the Fajr prayer on the Day of Jumu’ah in congregation.”
Reference: Saheeh al-Jamami wa Ziyaadah, Hadeeth Number 1119. Shaikh al-Albaanee (May Allaah have mercy upon him) said the Hadeeth is Saheeh.