Kuru Togas for sure for their rotating lead engine. The Advanced Upgrade specifically is my daily driver. The Pentel GraphGear 1000 is also a very comfortably hefty pencil. Otherwise the Pentel Orenz Nero and it’s auto dispensing lead mechanism is also really cool. Rotring 600 and Staedtler 925-35 are also popular pencils that I’ve tried and like, but I don’t own.