[user104658]

Originally Posted by Dia.

You can probably add House Umber to extinct houses too

Pretty sure Umber was a smaller / vassal house to House Stark anyway; there are a few of those to the larger houses like Mormont, Tarly, Karstarks, Clegane, Reed etc.

Houses like Tyrell, Tully, Martel, Baratheon and Frey were all major houses at the outset of season 1 that are now extinct.

Really the only major houses still in play are Stark, Lannister and Targaryen. Arryn and Greyjoy still exist but are effectively only tertiary players at this point.