[Null]

what do you mean when you say 'look like us' ?

do you mean look like us as in they could walk amoung us without being noticed? or do you mean the basic characteristics?

i think its very obvious that there is many other types of life out there, i think it would be absolutly silly to think the entire universe is empty besides us.
as to what aliens look like... it would also be silly to think we look like this, and every type of alien out there i looks the same but nothing like us. They'd all look different, they woulda evolved thier own way based on thier planet. So i've always thought of it the way Typhoid has said..

Lets say thier planet is all water, im sure theres an advanced (evolved) type of alien species out there that lives and breaths under water.
And theres other that have evolved breathing a different type of air, and all kinds of different things coulda happened during thier evolution.

Now what you gotta think is, the kind of alien that would visit our planet phisically would most likely have evolved similarly... so i'd say the chances of a alien (if ever visted here phisically) looking 'huminoid' (arms, legs, hands, eyes, maybe in much different perportions) are actually not too bad.