Maybe I should give my opinion on some of the bands mentioned here:
Mayhem: I remember borrowing a tape of them back in '95/'96 (maybe it was "Deathcrush") and I was like "Fuck, this sucks!!!". I then downloaded "Funeral fog" from "De mysteriis dom Sathanas" around a year ago I think and I though it was great. I got a hold of the record and as you see on my list it became one of my favorites. I have started to tire me a little though. Maybe it's because it's so simple. Let's face it, Euronymous wasn't the worlds best guitar player and all of "De mysteriis..." is really simple. Maybe it's the energy in the record that appeals to me and the good riffs. I also like "Grand declaration", but I think the clean vocals on that record is ridicolous! It kind of sounds like Maniac is rapping! I could have done without some of the electronic stuff on it too, but I can live with that. I have gotten a little used to the clean vocals, but I think the record would have been better if they had left it out.
Burzum: If you haven't heard them it's not what you typically categorize as black metal, as it's mostly around 150 bpm instead of 250bpm. It's really simple as well, but somehow it manages to stay superb after a long time. "Hvis lyset tar oss" has been my favorite black metal record since '95 or '96 I think. The vocals are extreme crappy, I agree with you there, but I've never found any good black metal vocals, so I have gotten used to the vocals.
Cradle of Filth: The only song I like by them is "She mourns a lengthening shadow" (ambient song from "Vempire"). I have "Dusk...". At first I was like "Yeah, that's pretty good", but after I listened to it 5 times I realized that there wasn't a single song I liked. Maybe 2 or 3 riffs that I liked, but that's all. The vocals are even more horrible than Varg Vikernes'. On top of that the band seem so corny!
Borknagar: I saw them live and when they played the first song I was like "Yeah, this is cool. I think I'll buy one of their records." After that the music got worse and they reminded me more of Bon Jovi than Emperor. The last song they played was good too.
Immortal: I have "Battles in the north", but I think it only has 3 good songs. The rest is pure noise. Even though Burzum also had bad production, Immortal's sound is so muddy and when their riffs are extremely muddy as well it just gets noisy after 20 seconds. I have "Sons of northern darkness" as well, but I've started to get tired of that after listening to it 2-3 times.
Ulver: Two first records are great! I think "Nattens madrigal" is pretty much pure noise and I've only heard it 2 times or something (I have the trilogy pic-disc box-set).
Bathory: I have "Under the sign of the black mark" which should be the most praised, so I wonder how bad the others will be, as I think there's only one good song on this, "Enter the eternal fire". I had "Blood on ice" once and it was pretty good as far as I remember, although it wasn't really black metal and Quorthon isn't exactly no Marvin Gaye!
Darkthrone: I have "Transilvanian hunger", "Panzerfaust" and "Plaguewielder". "Plaguewielder" is by far the best of those! Maybe a couple of riffs I could have done without, but not a bad song on the record, although it kind of needs a "classic"! The two others have 2-4 good songs on them and both have classics, like "Hans siste vinter" and "Skald av Satans sol". I have also heard "Under a funeral moon" and it's simliar to those two. Some good songs, but too many songs that I skip. It has their best track though, "Unholy black metal". It's primitive, raw, grim and ugly as hell, but I like it!! They have a lot of songs that I skip, but they're one of the bands in the world I have the most respect for!!!! Although they have evolved, they still play primitive black metal and hasn't made an attempt at selling out (okay, that greatest hits, but how many will buy that?).