To answer one of the OPs questions, yes, we do give more round the Holidays. But that is entirely because the "holidays" fall towards the end of the year, and it's important to get one's charitable contributions in before the end of the calendar year.
Our charities change from year to year, but those we do tend to always donate to:
Our Alma Mater (to the LSA college and specific donations to the fencing team)
Doctors Without Borders
My employer's charity (it's a hospital)
The Yellowstone Foundation
Unfortunately, our local humane society has...issues.