I know a couple of these are pretty well known but i thought we could share resources.
the big ones-
Matstation
https://matstation.com/
Love his stuff i use some of it for my combined army for infinity. it isn't really set in any universe which means it can be used in many.
The makers cult-
https://www.cgtrader.com/3d-models?author=themakerscult
more
40K themed but i love his WW1 inspired vehicle designs.
Station forge-
https://www.myminifactory.com/users/StationForge
Again more
40K aligned, but i own some of his admech inspired designs.
Now for some of the more obscure-
Marchen atelier-
https://www.myminifactory.com/users/Marchen%20Atelier?show=store
Its is a new one i found and it fantastically silly super deformed
40K....
Mel miniatures.
https://www.shapeways.com/shops/mel_miniatures
As a player of
B5 wars conversions including the expanded universe for star wars (supported in the
B5 wars ship sheets) this star wars armada compatible maker is pretty fantastic. i own many of his models
Unit 9
https://www.myminifactory.com/users/UNIT9#/
If your a fan of cyberpunk, infinity, ghost in the shell, apple seed, blade runner etc this maker has fantastic designs.
solwyte studio-
https://www.myminifactory.com/users/Solwyte/collection/terran-warhosts
I pretty much just love some of his sleek high tech looking
40K inspired designs for the terran warhost line.
Atlan forge-
https://www.myminifactory.com/users/AtlanForge?show=store
These
40K designs are so intricate and original with loads of love for obscure marine chapters.
Maelstromdesignworks-
https://cults3d.com/en/users/MaelstromDesignworks/3d-models
current day military vehicles what if they were in
40K designs.
Now for something close to my heart-
DUST 1947-
anerdsnerd-
https://cults3d.com/en/users/ANerdsNerd/3d-models
Dustified units-various WWII vehicles with DUST super weapons-
And romanovich
If your looking to find those out of print minis to build/finish your DUST 1947 armies.
https://cults3d.com/en/users/Romanovich/3d-models
I would be remiss if i didn't include the terrain section- as i have so much of this stuff 3d printed for various games.
40k/infinity/star wars legion-
https://www.warscenery.com/
MCP/infinity/star wars legion-
https://corvusgamesterrain.com/
40K/infinity scatter terrain- i have it mostly for the high tech industrial buildings-
https://www.myminifactory.com/users/forbiddenprints?show=store#/
the printpire- all things scatter terrain-fantasy/scifi etc..
https://theprintpire.com/collections/all
sacrusmundus-
40K terrain
https://www.myminifactory.com/users/Sacrusmundus
Hope that helps if you are looking for resources. post your own, there might be something i have not found yet that i don't know i need.
I also used to be a big fan of steel warrior studios for my classic battle tech terrain but now gale force 9 sells his designs and it is painted to boot so win/win