I think House is such a mess that it's impossible to figure out quite what's wrong with him. Take away the drug addiction, and see what's left... I think he's got BorderLine Peronality Disorder, as a result of being abused as a child by his father. (Really, it was shocking when he confides in one person what his childhood was like. See the episode, series of rooms.)
Frasier isn't aspie, he's just a snob. Niles on the other hand is definitely aspie, which might be why I'm so desperately in love with him. He's also a snob, but he has other traits that seem very aspie-ish. His affect is flatter than his brother's, he's more obsessive, and he has some truly splendid melt downs. My favourite is when he has a melt down in Cafe Nervosa, and has to take his clothes off they're choking him too much. By the time Frasier gets there Niles is sitting behind a newspaper saying, "i'm having that dream where I'm naked in nervosa..." Frasier replies, "I think we're all having that dream."
I realise that this is very exaggerated, but I've felt exactly this way myself. (Not that I've ever stripped in public. Or climbed into a freezer section in a supermarket, hugging the frozen peas saying, "why so cold, my love?") But melt downs often seem to hit me on public transport, eateries, or supermarkets, just as they hit Niles.
So Niles, my favourite fictional aspie. 