There are so many good places! A lot depends on what you like, what size, all sorts of things.
I am trying to not buy fabrics and have joined the Fabric Moratorium. Sometimes though I still need things and my first place is
https://www.equilter.com/
Been using them for years, always very good service. My local shops typically don't carry the Kona Solids I want, so I get them there. I like and recommend their scrap packs for stash building.
https://www.equilter.com/category/38...se-scrap-packs
When I am looking for fabric, I am often looking for some very specific things and so my next stop is Amazon. Long story but I had my Ebay user identity stolen and really try not to go there.
Several of my Amazon deals led me to this local chain in Michigan -- right from where my Hubby is from!
https://fieldsfabrics.com/
Seems to be the sort of great all around local fabric store that has completely gone out of business in my area.