Was Seinfeld the first geek TV show? We think so.
Today, the general consensus is that we're living in the most geek-friendly period in film and television. The most watched TV show is Game of Thrones, based on fantasy novels. The Big Bang Theory is a sitcom based on references to the culture. Even lesser entries like Gotham exist because of the increasing number of successful superhero stories out there. It's a state of affairs that was absolutely unimaginable 15-20 years ago, when television producers mostly largely avoided sci-fi/fantasy concepts and lambasted geeks as awkward shut-ins.
Except on Seinfeld, where geek hobbies were embraced wholeheartedly on mainstream television.
In "The Heart Attack", Jerry offers to bring a comic book to George's hospital room. In "The Chinese Episode", he takes George and Elaine to watch Plan 9 From Outer Space so they can mock it. In "The Voice", George cites The Incredible Hulk and "the old Spider-Man live-action show" to explain a burst of strength to his boss. At one point, Elaine even corrects Jerry on superhero lore, pointing out that "Rubber Man" isn't an actual superhero.
And that's not getting into the multiple times Jerry and George casually debate superhero logic at the diner, such as whether Iron Man has underwear beneath his armor. These moments aren't presented as awkward or abnormal, nor are geeky hobbies themselves the punchline of any joke. It's just a show about ordinary New Yorkers who occasionally stop to debate superhero facts and science-fiction tropes like it's the most natural thing in the world.
Remember, this aired a half-decade before Kevin Smith's Clerks suggested the behavior was normal. But throughout its entire nine-season run, Seinfeld unrepentantly wore its geek cred on its sleeve. "The Race" is jam-packed with overt and subtle Superman references. "The Strike" discussed "two-faced" dates in context to the Batman villain. "The Frogger" is an entire episode dedicated to the classic arcade game. Seinfeld constantly drew from superhero, science fiction, and video game tropes that mainstream audiences wouldn't be exposed to anywhere else.
Many of these geeky contributions were an influence of Jerry Seinfeld himself. In real life, Seinfeld is a massive Superman fan, even giving his son the middle name "Kal" for Clark Kent's Kryptonian alias. This appreciation carried over to his fictionalized counter-part and became a recurring quirk for the character: One of the very first episodes presents Jerry's argument that a yellow sun would enhance Superman's sense of humor. A later episode even reveals that his pin number is Jor-El, inspired by Superman's Kryptonian father.