Executive Meddling: Lou Ferrigno claims that Bruce Banner's name was changed to David because CBS thought Bruce sounded like a gay name.
That wasn't really the reason. Kenneth Johnson did not want the main character to have what HE regarded as a "stereotypically comic-booky alliterative name". Imagine his surprise when it was pointed out to him that his lead actor was called BILL BIXBY.
Hey, It's That Voice!: Ted Cassidy was the opening narrator for the whole series run and also growled and grunted as the Hulk (the first two seasons) while Lou Ferrigno walked around in green makeup.
What Could Have Been: Ironically, had Bixby not died, a fourth made-for-TV movie would have seen Banner resurrected, and with the ability to control his Hulk power, according to The Other Wiki. Apparently dying didn't exactly cure him. It just would have made it so that Banner could control himself when he transformed... that and actually talk, something the Hulk really didn't do outside of the two-part episode "Prometheus" when Banner was trapped halfway between human and Hulk.
You Look Familiar: Several times, most notably Gerald McRaney, who showed up in four episodes as different characters.
Cast the Expert: Rickson Gracie is one of the pioneers of MMA and an 8th-degree black belt in Brazilian Jiu Jitsu. He teaches Bruce some meditation techniques, and presumably some of the moves he uses on the thugs from the factory.
Fake Nationality: The cast used a few non-Brazilian actors to play Brazilian characters (the factory owner and the leader of the bully trio). Their attempts to speak Portuguese sound ridiculous to real Brazilians.
The Pete Best: Bruce ended up being Other Darrin-ed in The Avengers, which became massively popular while this film became relatively obscure (by Marvel standards, that is). As such, many fans are only familiar with Mark Ruffalo's version of the character and are unaware that Edward Norton was the first actor to portray Banner in the Marvel Cinematic Universe.
Remake Cameo: Like with the 2003 movie, Lou Ferrigno plays a security guard (this time interacting with Bruce Banner himself). And in a variant, a clip of Bill Bixby is featured at a certain point to feature both protagonists of the old show.