I've been obsessed with relistening to System lately because I got Radio/Video stuck in my head and decided to listen to it. Then I listened to Mezmerize and it carried on from there.
My album rankings would have to be:
Mezmerize
Steal This Album
Toxicity
Hypnotize
System of a Down
My absolute favorite songs are Sugar, Pepphole, Needles, Chop Suey!, Toxicity, Chic 'n' Stu, Mr. Jack, Fuck the System, Ego Brain, Thetawaves, BYOB, Revenga, Cigaro, Radio/Video, Violent Pornography, Sad Statue, Attack, Kill Rock 'N Roll, Vicinity of obscenity and She's like Heroin.
I realize this was a long list but I couldn't narrow it down lol