I really love the actual Fremont Street Experience. Every time I've been to Vegas (25+ times) we always go at least for lunch or a walk around.
The stores are cool for picking up a bunch of gifts for the kiddos at home and the food is reasonably priced pretty much anywhere you go. There is a few more expensive places you can eat within some of the casinos but its simple to find something more reasonable, there are adverts all over the place that price some of the most reasonable food.
Its close to the Mob museum which I had a great time at.
Also all the old neon is really amazing to see and you just don't get the same feel for it on the main strip.
Its always loud and upbeat. The performers are cool, though I stay away from the ones in costume looking to get tips for pictures, they are normally smelly/dirty close up and you don't really want a picture with that. Keep in mind, these people wear those costumes EVERYDAY.
My biggest complaint is that its dirty, right off the experience around any corner its gross and ghetto and there are homeless begging everywhere.
The artists with the spray paint are most assuredly my favorite thing about the Fremont Street Experience, having stood and watched them a sum total of 10+ hours throughout all my trips there and purchased multiple pieces, I really enjoy it and I think they are the reason that I go back every time I am there.