You need a very high tolerance for panhandlers, buskers, nudity, and crowds to enjoy Fremont Street. I got a huge kick out of getting my sixteen year old nephew's picture taken with a couple of cute "showgirls" and having my brother arrested by two sexy "cops". On the flip side, it *is* distressing to see young children dancing to support their parents and to see addicts pass out and fall off their levitation illusion contraption.
The overhead light show is a technological marvel and everywhere you look there's something to see. On the whole, Fremont Street is loud, colorful, wild, and completely overstimulating, but everyone should experience it once.