This large 99 Cents Only store on Boulder Highway is the largest in the immediate area. It offers a huge selection of "dollar store" items, and even a few which cost more than 99 cents. On my most recent visit, I purchased a 12-pack of toilet paper for $2.99. So everything isn't 99 cents, but most of their "over 99 cent" items tend to be relatively inexpensive.
As another reviewer said, some things you just don't need to over-pay for when a low quality item will do just fine. I've actually found a two-pack of decent disposable razors here that would easily cost $4-$5 elsewhere. It's definitely worth coming here and checking out the ever-changing inventory on occasion.
In addition to standard "dollar store" fare, there is a small grocery section. I have actually had pretty good luck with the produce, and often buy green peppers here. The bread selection is also respectable.
Obviously some items here are too cheap to be useful, such as certain tools, but overall I do like the selection at this location, and usually drive past a smaller dollar store to get here. I've always found it to be clean inside.
The lines sometimes get long, and it never seems like enough checkers are on hand.