I discovered this brand years ago when I found them reboxed at a bike shop. I have been purchasing Kenda tubes ever since. They are extremely consistent on the amount of air they lose over time. They have never let me down.
I've used these tubes in various wheel sizes & types. It's a good basic (non-racing) tube, a little on the heavy side. I like that it's available with various stem lengths & types. It's a little on the heavy side, but a great buy when you get them on sale!
The Kenda standard tube is a great value for the dollar. In my opinion this to provides additional protection against Flats. In addition it comes with a smooth valve option which will not tear up the grommet in your pump.