I have been knocking it out of the park with this crockpot version at gatherings lately. People can't get enough of it and it's easy enough. I do think it's important to boil the noodles to al dente before adding to the crockpot. I know some recipes call for you to add dry noodles and that's never worked well for me. But this hits.
https://amandascookin.com/crockpot-macaroni-and-cheese/
Obligatory PSA, never ever use preshredded cheese. Shred yourself or get the deli to do it for you. You need to avoid the anti clumping agents.
They're nasty and they screw up the recipe.
I add a Mexican blend of cheese and sour cream usually. I'll also do all sorts of variations if I have leftover chicken or bacon and I've fancied it up with lobster from the fish market in the past, too.