“When driving, watch out for old men in hats.”
Truest thing I ever heard.
When we got to an age when we were dating, my dad would always say:
“Men are scum; ask your mother.”
Both amusing and sweetly self-depricating.
Seconded by my dad.
Also, not ever said in a single sentence, but… laugh. Love life. Be jolly. Trust others unless they are grossly undeserving. Be friendly to strangers. OK, that’s a bunch of things, and maybe it’s not the shrewdest way to live, but certainly the most satisfying.
He said it to my son. I wasn’t there, but my son has mentioned it several time.
There was a sunset and they happened to stop what they were working on and watch it. So they were both looking into the distance.
Dad put a hand on my son’s shoulder and quietly said: “I’ve lived a long time. And one thing I can tell you. Farts will always be funny.”
cliche, but true: it’s easier to ask forgiveness than permission
total original dad: when you burp, pardon yourself at the same volume. that way you don’t have to explain the “pardon me” to people who didn’t hear the burp in the first place.
On doing business in the US (before my first trip there): “Speak more slowly and avoid contractions”.
Actually helped. 
Laughing out loud here, as that was my own recommendation to US coworkers* when we were going to be spending time with people from abroad. I added a third tip: do not use sports similes. “You refrain from talking about home runs, I make sure the Latin Americans refrain from sending balls to the corner.”
- mainly from Philadelphia, which means that their “can” and “can’t” sounded about the same to us foreigners, specially when talking fast. Oopsies!
“Never get married and raise your kids the same way.” It made me laugh, as a child. Makes me sad when I realize what he meant.
The two pieces of advice (out of hundreds of good ones) that have always stuck with me from my Dad are:
“Don’t ever apologize for anything unless you really mean it. People will know when you’re full of shit, and you just look like a hypocrite. Except when it comes to romance- you have to apologize to women whether you really mean it or not.”
“Trust me, you’ll never understand how women think.”
“At the very least, do the bare minimum.”
“hello mother, hello father, here I am in Camp Granada.”
Never did get that second one.
“Always pack more underwear than you think you need because you never know when you’ll shit your pants.”
“While the other guy is still talking about kicking your ass, punch him in the face.”
“You will not follow in my footsteps or I’ll trip you”
Not the most erudite man, but I don’t think he was wrong.
" When people start talking about politics or religion, put one hand on your wallet, and the other over your ass. Chances are they’re going to try to screw you one way or the other."
When faced with an impossible task, " would you like me to stand on my head and shit beebees too?"
From my father, a nuclear reactor engineer:
There is no problem brute force and ignorance cannot solve.
To get big matzo balls that are fluffy all the way through, poke a hole through them with a thin skewer.
“I’d rather owe it to you than cheat you out of it.”
“If you’re being bullied, stand up to the bully and BOP them on the nose.” His father had given that advice to him too.
Next time I was being bullied, I BOPPED the guy on the nose and got my head punched in.