my sister and i frequently have lunch at these "mom and pop" restuarants. it depends what kind of food you like.
if mediterranean try "hedari's" on sahara/buffalo.
for breakfast try "cracked egg" on cheyenne/buffalo.
asian food..anywhere in chinatown...
italian...i know buca di beppo is not exactly mom and pop but i really like the family atmosphere there.
most of the restuarants in hotels are not bad...mostly opened by top chefs.
you can also go to town square and they have a tuscanny restaurant ...they were really good and it is in an outdoor shopping area.that place is by far my favorite outdoor shopping in vegas.not too many ppl go there yet since not all the stores are open and they have movie theatre,book store,etc.
honestly though many restuarants open and close so the few i mentioned are those that stayed open. hedari's is good ...small , in the wrong location... i'm praying they never close.