Final answer:
Bryan Cranston played nitrous-oxide-huffing dentist Dr. Tim Whatley on the NBC sitcom 'Seinfeld' before 'Breaking Bad.'
Step-by-step explanation:
Before his iconic role in "Breaking Bad," Bryan Cranston portrayed a nitrous-oxide-huffing dentist on the NBC sitcom "Seinfeld."
Cranston's character, Dr. Tim Whatley, was known for his questionable office antics and comedic interactions with the main characters. Even in this earlier performance, Cranston showcased his versatile acting skills, which later earned him accolades for his role as Walter White in the critically acclaimed series "Breaking Bad."