Berserk Gene Tauros sounds fun.
That being said, in RBY Tauros was a crit machine. It single-handedly wins games at times, and other times it's a very reliable revenge killer and attacker in general.
After RBY, Tauros was no longer a crit machine. Hence, its fall from grace.
In GSC, aside from the Berserk Gene gimmick, it can be half-decent in modern GSC as a mixed sweeper with something like DE + EQ + FB + I dunno... Leer? Tauros outspeeds Zapdos, that's worth something in a mixed attacker. Surf + Thunder in the last two slots probably works better, though, to make life easier against Rhydon while giving it a chance to paralyze Suicune or Miltank. In the end though, it's kind of mediocre without something like Berserk Gene to give it that extra kick, as it otherwise fails to get past Cune and, in spite of its surprising bulk, still fails to switch in on anything or take any kind of hit. Not to mention that its damage output is kinda low since it relies on the strength of boring neutral hits rather than the super-effective super-hits with nice secondary effects that the other successful mixed attackers use.
CB Tauros in ADV is an off-beat but still very good Pokemon. Not exactly standard, but it's basically your textbook example of a good thing to pair with Magneton so it can get past Skarm and wreak havoc elsewhere.
Tauros in DPP just got nothing new and now had to compete with a metagame where its Speed was no longer special and its STAB was revealed to be sub-par.