Qpersonally COF are my #3 favorite band and always will be because their creativity and catchy level are amazing and there is no band that sounds like them. Granted, they have disapointed me greatly with Thornography and somewhat with Godspeed, I still love all their stuff and I'm glad they haven't resorted to breaking up or doing something they didn't have inspiration to do.
Even bands like Slipknot, Mudvayne, Tool, Bon Jovi, ect ect have some great songs and the memebers of the bands deserve respect because they truly are talented. They're not Opeth or Dimmu running around, but Tool is especially a great band. Just these bands make "simpler" types of music, and thus, is more appriciated by more people because of how many people can connect to it without having to over-analyze (unlike Opeth's music).
And about Dimmu, I think most of their songs sound bleh and kinda run together (especially on In Sorte), but i think Death Cult Armegeddon is one of the best black metal/symphotic metal songs known to man.
Now, I'm say one band that I do think is highly over rated and it might upset some since the singer is dead, but I honestly think Nirvana is overated. There's nothing that catches me with their music. (Metallica is overrated too but even they have a few good songs.) Oh yeah, and bands like Nile and Iced Earth...they are overrated how? Overrated means = far liked beyond deserving it (and usually by lots of people). I didn't know that anyone beyond this forum knows who Nile is, and the last time I seen a Iced Earth shirt at hottopic was 4 years ago. Not that I like either band tho.