I think my brother wants to remain untypable. I tried to have him take the Filatova test, but he stopped taking it after a few minutes, saying that he could relate to a couple points from every type he read. However, I have my own type test. There is only one question: what annoys you most about others? Being only one question, it's not the most accurate test, but I think it can help bring some types into the picture, and eliminate others. My brother's answer is that he's most annoyed by selfish people, and, to a lesser extent, both aggressive and rigid people.
Another key fact about my brother and I is that both of us are push-overs - but in different ways. While I have a hard time saying "no" to people, he can do this more easily (However, if they are persistent, he usually gives in.). On the other hand, I can shut people out of my life who are a nuissance more easily than he can. For example, there are two very selfish people who I'm glad to have out of my life who are trying to contact me through Facebook,. I've decided not to respond; I don't want to open Pandora's box again. He thinks I should talk to them. Another example is that there is one friend of his who is quite close to him who decided not to show up to my brother's bachelor party, just because my brother wasn't going to have any strippers. (It's my brother's party. In my opinion, he can have it any way he wants.) My brother was really mad about this. This guy also always uses my brother. If I were my brother, I would have used this as an opportunity to get this guy out of my life. I wouldn't tell him directly. I just wouldn't pick up the phone if he called. However, my brother forgave him, and they are on "good terms" once again. What does this sound like? Is there a type that is unselfish and despises selfishness in others, but can be treated like a doormat?
One last thing that I should mention about him is that he's now married. The woman he's married to basically controls their relationship. For example, if they're going to see a movie, it's always something she likes, or something they both like, but never something he likes. I think she's an ENTj or ESTj; she's very practical and very economical. She lives like she's poor, even though she makes a good salary as an actuary. I'm just throwing this in, but as for herself and I, I like her, but I feel that there's some sort of tension between us, like we're on different wavelengths or something. So, I suppose I could be an INFj, but, if she's an E_Tj, that certainly goes against it.