Reeves has developed a reputation as a pretty generous guy over the years, frequently choosing the artistic integrity of his projects over a huge payday. This short summary really tells most of the story, in a very sad way. (Even though Keanu does approve of the Sad Keanu meme.)
But Keanu fights on and continues to be one of the greatest celebrity philanthropists around.
He really does subscribe to the idea of all people being "excellent to each other".
He told Hello! Magazine in 2003: "Money is the last thing I think about. I could live on what I have already made for the next few centuries." Give or take a few hundred years. (It's true that Reeves has appeared in six movies that have grossed over $100 million, which isn't really a bad haul.)
1. The Devil's Advocate: When making The Devil's Advocate, Reeves agreed to take a big pay cut of a few million dollars (a few million dollars) so the producers could also afford to bring on Al Pacino. (He perhaps somewhat selfishly did have the fate of the movie itself in mind. One shudders to think of anyone else performing that climactic monologue other than Pacino. It wouldn't have quite the same zing with, say, Christopher Lambert in the role.)
2. The Replacements: He did the same thing on The Replacements, allowing producers to bring on board Gene Hackman by demanding less cash up front for himself. He actually took a 90% paycut.
3. The Matrix: But the real generous side of Keanu (that doesn't have to do with giving millions to charity) came out when he was making his back-end deal for the two Matrix sequels.
True, Reeves was paid $10 million up front to film the The Matrix and ended up earning $35 million total after the film became a huge hit. But still, when negotiating his profit-sharing deal for the two follow-up films, Reeves opted to hand over some of his points to the franchise's special effects and costume design teams. The total amount Reeves could have earned but chose to disburse to the crew instead comes, by some accounts, to over $75 million. He donated over $75 million to people he worked with because he thought they deserved it.
And in one personal account on Reddit, he helped out a family in need.
A family friend builds movie sets, doesn't design, is one of the poor dudes that just builds. Anyway, he worked on the set for the Matrix and Keanu heard about family trouble he was having and gave him a $20,000 Christmas bonus to help him out. He also was one of the only people on the set that genuinely wanted to know peoples names, would say hello and mean it, and would talk to people as they were his peers and not below him just because they were practically making nothing to build a set. I've never heard anyone say Keanu is douche, seems like the nicest person in Hollywood from a second hand experience.
Also of note? Reeves gave the entire stunt team behind the Matrix sequels Harley Davidson motorcycles.