Urban dictionary definition of "anti-hero":
An anti-hero is a flawed hero, and therefore, much more interesting than the more traditional heroes. They can be working on the side of good, but with a tragic flaw, or a horrible past, or for reasons that are selfish and not entirely "pure". They can also be working for the side of evil, but with hidden noble intentions, or other underlying complexities. These darker heroes can be jerks, pathetic, hard, jaded, or mean. However, all anti-heroes must have enough heroic qualities, intentions, or strength (physical including attractiveness or mental) to somehow gain the sympathy of the audience.

Sums Magneto up I think.

Well of course it's hard to make this argument for him in the original 60's comics but he's been fleshed out since then and he's been working with the X-Men for some time now. He can really get away with a lot of stuff just by mentioning the word Holocaust. I've always liked him and if I don't call Wade a villain I can't call Erik/Max/whatever a villain

I'm kind impressed that I'm not the only one out there who sees Magneto as an anti-hero though I gotta admit before "X-Men: First Class" I saw him as a villain too but now I actually understand him completely. Why Erik became Magneto and his reasons to it.

Erik/Magneto is honestly not really what I would consider a villain. I mean yes to some people that is what they see but for someone with a history like mine, his motives are understandable and to be open about it I would not hesitate a second with getting revenge on the people who destroyed me if I had a chance at it!

<3