Someone I work with used to live in Laughlin. She worked at the Edgewater. She said she wouldn't stay in either the Colorado Belle or Edgewater, because they are dirty. The Edgewater is newer than the Colorado Belle, but both are dumps, according to her.
+1 on the Aquarius. Its right next door to Edgewater/Colorado Belle and it is much nicer. They usually give you breakfast free when you book through their website - and their diner rocks.
Aquarius location is better than Harrah's in my opinion. Rooms are decent. Be sure to ask for the California tower (no kids). Pool though is pretty boring and mediocre. Right in the center of things.
Harrah's is all by it's lonesome up the hill but does have a little "beach".