The 2010 TIME 100

Every comedian I know is a pain in the ass. I've done movies with some of the best, and offscreen I enjoy their company a lot. Everything is played for laughs; nothing is sacred; it's all about them. But it's fun, so you live with their mishegoss.

Ben Stiller, whom I got to know on Meet the Parents, is different. Oh, he's still a pain in the ass — sometimes a total wacko — but he also has an old-fashioned sense of respect. (I don't mean in the Mafia sense, but yes, in that way too.) He has a quiet, intelligent side that I really appreciate.

Relationships between actors can be odd. We say we're friends even when we cross paths only every year or two or three. Ben is different here too; I know he's there for me. He came to my wedding and recently surprised me by being there to honor me at the Kennedy Center. But that's Ben. Invite him to your wedding ... you'll see.

It may be that my friend is unique — a deeply comic spirit and a deeply kind spirit. He sees all that's strange, quirky and funny, but he's not blind to what's ugly, sad or tragic. When Ben recognized the need to provide schools for Haitian children, he found a way to do it by combining humor with humanity. He founded StillerStrong.org with the slogan "Stealing great ideas from other charities." You log on for the jokes, then stay because Ben has moved you; and before you know it, you've made a contribution, and the world's a slightly better place. What a pain in the ass.

De Niro is an actor, director and producer

TIME 100 Social-Networking Index: 1,735,285