All the suggestions are brilliant. Many are close to heart either because local or through experiences we have had,however I agree with #145.
For most of the charities mentioned the people who benefit will in some way have it obvious their plight. Be it cancer, terminal illness, homeless etc.
Some of these will get occasional special treats and holidays and no doubt family treat them dearly.
Going back to #145 abused children suffer in silence, all year round. Noone gives them treats or gives them an extra hug for their suffering. Noone can often see the visable scaring and torture they go through. So maybe NSPCC or childline would be a good choice.