Straightfoward, got the point in current content where playing the game with pugs is insufferable. Dont need any sweaty hardcore guild but people that know what they are doing, so nothing thats very casual either.
I would have a friend or two to bring with me, tank and dps.
I mainly did keys and finished heroic raid, would like to get into mythic raid and +20 plus above keys.
I have a full time job almost every day so raiding hours that dont stretch way past midnight would be cool.
Friendly enviroment and fun first is most important though.