I’m looking for something very similar to 90s Megadeth. Think “Skin of my Teeth.” (Or possibly 90s Metallica or older Black Sabbath or 90s RATM.)
But with mainly the heavy low level bass, and palm muted guitar power cords, without so much of the mids or highs (like vocals and guitar solos.)
Like bass intensive but not super fast like Slayer or double-pedal drum stuff.
Any ideas?
Stoner/doom/sludge is probably what you should be looking for.
Try bands like My dying bride, Electric Wizard, Sleep, Kyuss, Stoned Jesus, or maybe even bands like Paradise Lost or OM.
And then there’s Gnome ;-)
Sounds like doom or some if it’s subgenres should be up your alley? Would recommend you check out stoner bands like Kyuss and Sleep and explore from there!
Sounds like you want something like Doom Metal, so I was gonna suggest Candlemass but the vocals are kinda high.
Down has some great riffs and Phil Anselmo’s voice is definitely low, you should try their 2nd album (most interesting for the bass part) : “A Bustle In Your Hedgerow” https://youtu.be/YSdfwOEGFhI
Infectious Grooves maybe? Metallica’s Rob Trujilo on bass.
Sludge metal?
If you want slow and bass intensive, there isn’t a much better example than Meshuggah. Check out the song Rational Gaze. The first song that came to mind by that description was https://open.spotify.com/track/6qgpRSh8GbK7xkchhoaoaD
If it has to be 90s, nothing comes to mind for now.