i can usually tell if i like a band or not from one song.

Depends. Some bands get me right from the first riff (Dillinger Escape Plan). Some bands I hear about try one song, go meh, come back to it a couple of hours later and it makes sense, at which point I devour the rest of their catalogue (Oceansize).

Some bands I flat out don't get or just can't be bothered with. Their record gathers dust for a couple of years. I come back to it and suddenly it rules (Elbow).

Some bands I will never, ever support, alive or dead (other bands).

and if it's recommend, do so lots until I finally 'get' it, the point when you can sort of anticipate the songs and have some sort of attatchment to the music.

i've heard at least one album of. Many times. I could rate loads of bands that i've heard a few songs of but it would probably be wrong.

On the internets these days I swear there are actually bands that nobody actually likes, but are 'rated' highly.

The exceptions in my case are HIM and Scott Weiland. They are simply very, very bad.

theres bands who you have one album which you think is amazing so you rate them ten, but then when you listen to all their other albums they pale in comparison, should you lower your rating even though you still think that one album is amazing?