Ok, we can do that, lets see.
Slayer: not really into their religion but I do respect their contribution to the field.
"Religion"? They are atheists as far as I know, Hanneman definetly is anyway. The "satanic" thing is a gimmick. They were primarily inspired by horror movies for there "evil" lyrics.
Iron Maiden: I haven’t really met a person that doesn’t like Maiden !
Morbid Angel: I did like heretic a lot but haven’t yet spent time listening to their music, that’s because I think they are just ok when there are so many bands I like more.
In that case if you haven't already done so I HIGHLY recommend the first three albums by them: Altars of Madness, Blessed are the Sick and Covenant. Each is totally excellent and a classic of the genre.
Emperor: haven’t checked them out but of all I hear from friend they seam to be good.
Like the previous group check out their first 3 albums: In the Nightside Eclipse, Anthems to the Welkin at Dusk and Equilibrium IX.
Cannibal Corpse: there guys (along with 6 feet under)I don’t like. I think they are pretending to be so mean and Gore, just for attention. Singing about digging up corpses and having sex with dead children but I bet they would be scared shitless if seeing a dead body.
Yes in interviews they have said that their lyrics are not to be taken seriously. If they were serious about that stuff they would all be in jail. The lyrics are meant to go along or fit in with the intense music they created. If you haven't heard much of the group my recommendations would be to ignore they lyrics and check out: Tomb of the Mutilated, The Bleeding and Vile.
Dimmu borgir: their music is not bad. I don’t own any of their albums but I seam to like them. What I don’t like is their attribute with the inverted crosses and pentagrams. Its not like I have something against it, it’s just that I think they are faking it to look more evil.
The whole "satanic" thing here is also just part of the whole black metal imagery. So no they aren't really satanic at all. For me if a band has some satanic lyrics/imagery and they are faking it it doesn't bother me, I look at it like they are telling scary stories set to music. Check out the following albums: Stormblast (original version), Enthrone Darkness Triumphant, Spiritual Black Dimensions and Puritanical Euphoric Misantrhopia.
Cradle of Filth: I have 3 of their albums and listen to them regularly but to explain if I like them is impossible since I haven’t still figured out what kind of music they play. P.s. I think they are faking it too but there is no doubt that Danni filth is a great musician.
The best albums by Cradle are the first 4: The Principle of Evil Made Flesh, V Empire or Dark Faerytales in Phallustein, Dusk... and Her Embrace and Cruelty and the Beast. As far as faking it: there have been SO many different members in this group that for one you can't expect them all to believe or practice the same things. Dani however is the main voice (no pun intended) for the group and all the imagery/lyrics/subject matter comes from him. From what I know he is not a satanist (satanism really is only a small part of the groups lyrical content as they focus more on vampirism, the occult, dark neo-paganism, etc.) but has experimented with the occult.
King Diamond: The same with slayer. Respect but no thanx !
Mercyful Fate: not heard much of their stuff so i really cant tell.
King Diamond/Mercyful Fate are frankly two of the most classic metal bands ever. As far as King Diamond's "religion", he did indeed join the Church of Satan and was friends with Anton LaVey, however he doesn't actually pray to the devil or put curses on people. LaVayan satanism is primarily an atheistic humanist philosophy of self gratification with occult dabblings thrown into it. They do not actually believe in the literal existence of satan. As far as their music every metalhead NEEDS the following three Mercyful Fate albums: Mercyful Fate EP (re-released as The Beginning), Melissa, Don't Break the Oath. For King Diamond you need: Abigail, Them and Conspiracy. Frankly I think the two Mercyful Fate LP's listed and Abigail are 3 of the best metal albums ever made.
Type O Negative: some times I wonder if I am the only one who likes them.
Yes great band. I own every album of theirs but none of the DVD's, the best of, or any singles/imports.
There you go ! as for may favourite bands: ozzy,opeth,dark tranquillity,lamb of god, amon amarth,motorhead,bling guardian, rotting C, nightwish, anathema and more.
Of these I've only listened to Ozzy and Opeth. The first two Ozzy albums are of course classics. He's released a number of good tracks since then but no albums of the magnitude of the first two. As far as Opeth I have not heard any of the early material only the material from Still Life to the present. I loved Blackwater Park but frankly I found the rest of the material rather dull.
Oh, I also should have added Judas Priest and Black Sabbath to my list. Ozzy era Sabbath is great (first 6 albums) and just about everything Priest did from 76-84 is great.