Oh my Allah! Why are people so flippant with the word haram?! No, it is not haram to judge people's level of attractiveness based on their looks. Yes, it is haram to judge someone's deen based solely on their looks because Allah says He will look into our hearts to know if we are really good. ANyway, just don't be a snob if you're gonna judge others. At the same time we all judge. Alhemdullah I have good instincts and can *usually* tell a nice person from a creep from an untrustworthy one etc.
Allahu'Alam. Masalams.