I'm sorry you had such a bad experience with Las Vegas.
I happen to love it there. My son lives out there now, in a very nice apartment complex. The area around his complex is really safe also. Which to me as his mom, makes me feel good. To me their are some very nice area's of L.Vegas and the surrounding towns. Like Red Rock Canyon in Summerlin, The Hoover Damm, but you do need a car to drive to those places.
Before he moved out there, we always stayed @ the Mirage on the strip. I really liked that hotel and the area around the hotel was really nice. Although I do agree there are some hotels in L.Vegas that they really need to implode/tear down. I also agree about Fremont street though. Their light show is something to see, but the area directly off Fremont Street, is not good.
There are a lot of nice mid priced restaurants off the strip also. But there again, you would need a car to get to them.
I think any big city has their share of problems. Again, I'm sorry you felt that way about L.Vegas.