Currently I am running one homebrew (New Mavarga, using a 7th Sea heavy variant as the base rules) and playing in another homebrew (Khal'adjir, using an L5R heavy variant as the base rules).
There are a few published worlds I might play in someday. I have played in Prax (RuneQuest), Mythic Europe (kinda my own take, though ... Ars Magica), Britain (Pendragon, though again with severe variations), and even Night City (Cyberpunk); I have been in a few D&D adventure modules, but the background worlds themselves (Greyhawk, Forgotten Realms, other) seemed to have little to no impact on the play of the adventure itself.
For the most part, I am a homebrew guy and will stay that way until the end. That way I have all the "support material" I will ever need.