Where to go after O&S and painted world?

So I've beat Taurus demon Goyles Moonlight butterfly Sif Capra demon Depths Catacombs (visited tomb of giants, is there a boss?) The one Dragon in Valley of the Drakes Blighttown Got the shortcut to Abyss opened in New Londo Ruins

Currently stuck on The 4 Kings and want to do something else. I haven't gone up and to the left in Anor Londo yet. Where else can I go?