Before Wrestlemania III, Vince wanted something huge. So he was trying to convince André the Giant to come out of retirement to face Hulk Hogan for the main event. Andre declined, as he had severe degenerative issues in his back that caused him great pain. Vince convinced him to talk to the best doctors in the country about a radical surgery, vowing to pay for it whether or not Andre competed. He came through on his word, not only giving Andre an unforgettable send-off, but relieving him of an immense amount of pain at the same time.
Mick Foley was in the middle of an amazing run as his Mankind character. He could have milked it for a lot longer, but he didn't. Vince gave Mick the chance to wrestle as his boyhood persona of Dude Love. Not just for a night, but permanently. He was willing to give up a known success just to give Mick the chance to live his dream. Here it is.
Say what you will about Super Cena, but one of the main reasons Vince has refused to give him a Face–Heel Turn (and lose out on the huge possible profits that might lie therein) is because Cena loves doing charity work (especially for the Make a Wish Foundation) and being a heel would interfere with it.