I like this kind of music, always have, and recently I've been checking out some newer bands who (I think) fall into the doom genre, broadly speaking (I'm never very comfortable with trying to pigeonhole music into all these genres and sub-genres, but they can be useful sometimes, I guess).
I very much prefer the more melodic, '70s-influenced, old-fashioned trad metal end of the spectrum. I do like the really sludgy, grindy bands like Sleep as well, but I can only take them in small doses, to be honest.
Can't claim to be any kind of expert - the bands I like are probably only the better known ones and I'm probably just scr@ping the surface really.