Original games as in what made the Battletoads franchise what it is (or was), drawing a destinction between then and now. Also "original games" as in, why reducing Battletoads to one game? You say the original wasn't very good, but what about Battletoads Battlemaniacs and Arcade? The "baseline" is definitely bigger than one "original game".
Are you being pedantic on purpose? We're talking about a series where the first game is by far the best known and upon which everything else is based. Even one of the games you mentioned is basically a remake and the other was a bomb that almost no one played. The original game is the baseline for the franchise, like it or not.