Some great lines from Cuckoo's nest

Not really a great line in and of itself but in context this observation at the end of Part I where the patients defy Big Nurse in the small way that they can by sitting around a dead TV screen not watching the World Series is so intensely liberating:

If somebody'd of come in and took a look, men watching a blank TV, a fifty-year old woman hollering and squealing at the back of their heads about discipline and order and reciminations, they'd of thought the whole bunch was crazy as loons.

And Chief's reflection on the danger of sticking your neck out minutes later:

I'm just getting the full force of the dangers we let ourselves in for when we let McMurphy lure us out of the fog. 

One of the Acutes is named Harding and there are suggestions that he might be homosexual. Or just a feminine guy. And has a cruel wife. She comes to visit one day when the patients are in the library and he asks McMurphy afterwards what he thinks:
"Hell's bells, Harding!" Mc Murphy yells suddenly....."All I know is this: nobody's very big in the first place, and it looks to me like everybody spends their whole life tearing everybody else down. I know what you want me to think; you want me to feel sorry for you, to think she's a real bitch. Well you didn't make her feel like any queen either. Well, screw you and 'what do you think?' "

Chief Bromden's observation about McMurphy on the fishing trip:

Maybe he couldn't understand why we weren't able to laugh yet, but he knew you can't really be strong until you can see a funny side to things. In fact, he worked so hard at pointing out the funny side of things that I was wondering a little if maybe he was blind to the other side, if maybe he wasn't able to see what it was that parched laughter deep inside your stomach.

And Harding's on their discovering, with McMurphy's help, the potential for intimidation the perception of mental illness bestows:

"Never before did I realize that mental illness could have the aspect of power, power. Think of it: perhaps the more insane a man is, the more powerful he could become. Hitler an example. Fair makes the mind reel, doesn't it? Food for thought there."

On the laughing miracle that happened on the fishing trip:

While McMurphy laughs....Because he knows you have to laugh at the things that hurt you just to keep yourself in balance, just to keep the world from running you plumb crazy. he knows there's a painful side...but he won't let the pain blot out the humor no more'n he'll let the humor blot out the pain.

It started slow and pumped itself full, swelling the men bigger and bigger. I watched, part of them, laughing with them-and somehow not with them. I was off the boat, blown up off the water and skating the wind with those black birds, high above myself and I could look down and see myself and the rest of the guys, see the boat rocking there in the middle of those diving birds, see McMurphy surrounded by his dozen people, and watch them, us, swinging a laughter than rang out on the water in ever-widening circles, farther and farther, until it crashed up on beaches all over the coast, on beaches all over all coasts, in wave after wave after wave.

And this bit of foreshadowing (along with the men being unable to stand up to the louts at the dock without McMurphy right beside them) that kind of makes me wish the book ends at Part III:

Then-as he was talking-a set of tail-lights going past lit up McMurphy's face, and the windshield reflected an expression that was allowed only because he figured it'd be too dark for anybody in the car to see, dreadfully tired and strained and frantic, like there wasn't enough time left for something he had to do...

Chief's last moments with McMurphy:
I looked at McMurphy out of the corner of my eye, trying not to be obvious about it. He was in his chair in the corner, resting a second before he came out for the next round-in a long line of next rounds. The thing he was fighting, you couldn't whip it for good. all you could do was keep on whipping it, till you couldn't come out any more and somebody else had to take your place.