Yep. Humanity, humility and humour. Always attractive as a combination. I also think the name matters. If a name is just a series of unpronouncable letters and numbers, that tends to put me off a bit. Not once I start reading the post, but as a first impression.
It's difficult really to determine what it is that makes posters 'attractive'. It isn't just the fact that someone is likeminded. I mean, I disagree with pretty much everything UG says, yet I am attracted to his posts and would even go so far as to say I like him as a character. But likeminded helps
I generally will check out posts by those I am 'attracted' to: SG, Elspode, Hip, Happy monkey, Sky, rkzenrage, to name a few.
I have never heard of the term 'lookism' before btw. It tends to be referred to as 'body fascism' over here.