I feel like Viserys gets a lot of hate that he doesn't deserve (TV show fans mainly, not seen Viserys discussed here much, and you guys are my only book-reader friends)
Almost his entire family were murdered and he was forced into exile to a foreign land, being passed from noble to noble as welcomed/unwelcomed guests, eventually having to sell his family's most prized possessions just to feed himself and his sister, which is heartbreaking IMO, whether you like the targs or not. He was probably lauded over by these lords as 'The last Dragon' 'The rightful king' yadda yadda, these things alone are enough to give you madness and a superiority complex, let alone 100's of years of inbreeding. Viserys never had a proper father figure, to teach him right from wrong, (How long was willem darry alive for?) His anger towards Dany for "Killing their mother" isn't justified but I can understand why, he was torn from the last living member of his family, his mum, for a new sister who he had to raise and feed at the expense of her crown.
He gets hate for his sexual advances towards to Dany, thats a non-starter, we know the Targaryen customs.
He gets hate for "selling" Dany to Drogo. No different to the lords of westeros betrothing their sons and daughters to other lords' kids. and Dany eventually loved Drogo, how often does that happen?
Dany herself understood the turmoil that must have went on inside Viserys head
The only thing I can't justify about Viserys is his violence towards Dany and threatening her unborn son, but from his POV, he was drunk(?) and felt aggrieved that things werent moving fast enough to re-take the throne. He gave up his sister/futurewife for the promise of a Crown and it just wasn't happening fast enough, but i can't justify it, dick move. I don't think he really would have cut or killed Dany. He was mad, driven mad by his blood and all the things that happened to him.
My inspiration for this post came from the Tyrion-hate threads, where certain people where trying to justify Tyrions rapes, and murders, and usurys, and abuses, and alcoholism, and scheming and kinslaying because of his upbringing. Can Viserys then be excused from his crimes because of his equally bad upbringing?