I'm a fan (and you should be too) because... Adam's voice is amazing! The first time I saw him on Idol was when my mom told me how great of a singer he was and to vote for him on my phone because she doesn't text too well. I saw him sing one song and all I said was, "wow." He adds so much personal style to his songs and appearance, how could you not be a fan? 
Sorry to the other people singing but I'm really only going for Adam!