Very good. Love the Lord your God with all your heart, soul, mind and strength and you neighbor as yourself. walah, two commandments.
So we have one, two, and three so far,
1. Love God
2. Love thy neighbor,
3. Love one another.
Here's my candidate for a fourth:
Mat 5:43-44 KJV
(43) Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy.
(44) But I say unto you,
Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;
Notice the pattern? I think there's a few more out there. There's an implied "love truth" in 2 Thessalonians 2:10 but technically that isn't spoken by Jesus. It is spoken by the Holy Spirit if you allow for inspiration of scripture. I would suggest that the commandments of Jesus can be summarized by their first word "Love" and the additional parts following boil down to that, in essence.
Mat 28:19-20 KJV
(19)
Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
(20)
Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.
That would make a commandment number five, and although it doesn't use the word "love" in its text, isn't that an expression of love? And aren't the things that you are supposed to teach all nations to observe all summarized by "Love..." also?