This is the only cause I donate money to, when I'm able to donate anything at all:
All Hands on Board Marketplace
Tucker is a friend from college, he's been living with ALS for over a decade now. He's absolutely brilliant and helped design the intricate computer system he uses now to help him communicate and do his artwork. He lives at home with a small 24/7 professional nursing staff. There are dozens of other unpaid volunteer "caretakers" for Tucker, from his immediate and extended family, to lifelong friends he's made, to friends he's made through his former job in the film industry. It costs around $10,000 per month for Tucker to just - live. Disability and medicaid covers a good amount of it, but not all.
Edited to add: if you felt you needed to receive something in return for a donation, you could just buy some of his artwork instead of donating. I think he'd probably like that even more.
Tucker Stilley
He can't eat, breathe, eliminate waste, without machines. He has no ability to move any part of his body, other than his eyes, and I believe he can still twitch his lips to smile on one side of his face. He is non-vocal, but communicates by computer with a special device that tracks his eye movements (one of the few muscles he still has control over).
His art is unworldly, and he has a team who helps him with gallery exhibitions (he attends via live video streaming from home). Tucker and his wife Lindsay are two of the most remarkable people I've had the honor of knowing. Lindsay is a true warrior woman, a talented film editor, devoted caregiver and childhood love of Tucker's, and fierce mama-bear to their daughter Juno (who is exquisite in her own right). I met Lindsay first, she lived two floors directly beneath my dorm room when I was in my second year at Emerson College.
100% of all donations goes directly to Tucker's care. The family takes no "administrative fees" and pays the pay-pal fees themselves unless the donor chooses to do it for them. The Cohort for Disembodied Artists (the name of his non-prof) is a true non-profit charitable organization and donations are tax deductible.