Umar Ibn Al-Khattab (Radhiallahu Anhu) said..

I looked at all friends, and did not find a better friend than safeguarding the tongue. 

I thought about all dresses, but did not find a better dress than piety. 

I thought about all types of wealth, but did not find a better wealth than contentment in little. 

I thought of all types of good deeds, but did not find a better deed than offering good advice.

I looked at all types of sustenance, but did not find a better sustenance than patience.