Another good one is MG Chemicals
For flux, Chemtronics is good too
Keep in mind places like Ebay and Amazon Marketplace may try to sell no-name stuff as one of the name brands, or they may try to sell you old product that may not work as well. I'd only order from an actual electronic supply company (Mouser, Digikey, Newark, Allied, etc.) or possibly Amazon (NOT the marketplace / third party sellers unless it's a known-good seller).
Edit: Oh, and I'd like to add to the question a bit. Anyone know if there are any good Made in USA brands of solder/flux? This wouldn't matter to the non-US people here, but I'm from the US and would like to support the US economy when possible... Is Interflux a good brand for flux? Any good ones for solder? I buy from the brands already listed by OP and myself, currently...