I'm a martial artist, have been since I could walk, so a lot of my favorites revolve around that, along with the philosophical and strategical aspects of fighting and conflict.
I have hundreds but here are a few of my all time favorites.
"When your time comes to die, be not like those who's hearts are filled with fear of death, so that when their time comes they weep and pray for little more time to live their lives over again in a different way. Instead, sing your death song, and die like a hero going home" Tecumseh
"The fastest draw is when the sword never leaves the scabbard. The strongest way to block is to never provoke a blow. And the cleanest cut is the one withheld." Gichin Funakoshi (founder of Shotokan Karate)
"There are no contests in the art of peace. A true warrior is invincible because he contests with noting. Defeat means to defeat the mind of contention that we harbor within." Miyamoto Mushashi
"I fear not the man who has practiced 10,000 kicks once, I fear the man who has practiced one kick 10,000 times." Bruce Lee
"Courage is doing what you're afraid to do. There can be no courage unless your afraid."
"Feeling important makes one heavy and clumsy. To be a warrior one needs to be light and fluid."
"Given enough time, any man can master the physical. With enough knowledge any man may become wise. It is the true warrior that can master both. And surpass the results." Tien Tai
"Pretend inferiority and encourage his arrogance." Sun Tzu
"If the wind will not serve, take the oars."
"Strength does not come from physical capacity. It comes from indomitable will."
"An expert is one who knows more and more about less and less"
Oh and one last all time favorite.
"Love many, trust few, and always paddle your own canoe."
Anyone that has ever sat in the front of a canoe with another person paddling will understand this one.
Jon