Everyone is discriminated against, but the the things that are discriminated worst against are the things that someone wouldn't know unless you told them.
Polls have shown that Atheists are the least trusted minority in the U.S. More parents would object to their child dating an atheist than any other group. The people would rather elect a homosexual or a Muslim than an atheist.
I was actually in a situation where I was dating a girl, and her mom was talking to her about what my religion was. The girl said I wasn't a Christian. Her mom replied that "as long as he isn't an atheist, he's fine by me". I had to tell her that technically, even though I don't choose to use that label to describe myself, I am technically an atheist.
Where I live, white people are a minority(more Mexicans than anything), and there is some tension between Black people and Mexican people. In some parts of Chicago, I've known white people who were highly xenophobic. Racism is still around, and discrimination is a VERY real thing. You don't usually realize it until you are a minority of some sort.
I don't think I'm discriminated against for being white though, If I do get discriminated for my looks, it is probably because of the fact that I have ridiculously long hair... and unless I'm playing on stage or something, I look like a grunge artist or something.. Pay no mind to the 40 of malt liquor hanging from my hand.