Early-mid 90s black metal is really the only thing I care about anymore.
In some sort of vague order:
Mayhem
Darkthrone
Burzum
Emperor
Immortal
Ulver (Bergtatt - Nattens Madrigal)
Enslaved (early, early)
Graveland
Drudkh
Beherit
Aeternus
Deathspell Omega
Blut Aus Nord
Vlad Tepes
Mutiilation
Belketre
Fuck Torgeist. They suck.
The bands I've just listed mean more to me than 99.9% of all of the people I'll ever meet. That means that only one (whole) person in 1000 will mean more to me than these bands. Damn.
80s
Bathory
Hellhammer/Celtic Frost (I guess I'll include the latter - can't hurt)
Venom (when you call them "gods" (sic) could you please make sure you do it with a Z?)
Sodom (pre-Persecution Mania)
Kreator (yes, I'm serious - go listen to Pleasure to Kill, right now, and tell me it doesn't sound like De Mysteriis Dom Sathanas. Endless Pain is also early black thrashing noise.)
Sarcofago
Destruction (c.f. the first ep)
Slayer (show no mercy is the bastard child of venom and bathory)