We stayed over night a several times in the past couple of weeks at Hollywood Park Race track and Casino in Inglewood, CA. You have to be careful to be in the casino portion of the parking area though. They will not let you stay in the race track parking and if you park so that your rig is outside of the designated parking lines at all they will have you move or tow it away if they can not reach you for any reason.
As you enter the main entrance there is a sign with an arrow indicating the RV parking area.
Of the four or five nights I was there only once did they bother me and it was due to my being about six inches out into the "roadway" at five AM when the parking lot was nearly deserted. However, the security guard just asked me to move my rig down to the area where most of the RV's were and that was that.
- level lot? YES
- walking distance from casino? YES
- well-lighted? YES
- quiet? YES
- security issues? The lots are patrolled by security guards 24/7
- other... Not sure if it is technically allowed but I ran my generator on occasions and no one said anything.