To me, Fremont street is where it is at!!!! There is a shit ton of things to do, live bands to watch and dance to! It is definitely different then the strip!
It's way more laid back, not as much walking and everyone there is there to have a fantastic time.
They keep the streets extremely clean and there is a good amount of security and everyone is a blast!
There are so many random photo opportunities for things you will only see in Las Vegas! Definitely don't pass up the opportunity to see Fremont street!