I guess you could say Venture shares some of the same traits as Berzerk.
Too bad you're limiting the topic to the 2600, else I'd say Space Dungeon for the 5200. Also, as most of everyone here knows, Robotron was directly inspired by Berzerk, except with the tension level turns up to eleven, plus an extra dose of crack. Williams' most intense game, to me anyway. Too nerve-racking for my tastes.