SerperiorThanU posted...
Golem because it's the underdog and practically nobody brings up a Geodude all the way up to the lategame to use Golem.
Fun fact (which most people probably know about, but still): No NPC trainer in any of the Gen 1 games ever used Golem on their team. Meaning that--taking into account the other choices between Pokemon players made (starters, the Hitmons, the Fossils, the Eeveelutions)--it's the only Pokemon that you are guaranteed to never see unless you got one yourself.
They could have at least replaced the second Onix on Bruno's team with a Golem.