Rugs, Carpets and Carpeting - Flooring Options

I'm in the process of finishing the basement and am now ready to put in the flooring. I am going to put in both sheet vinyl (1/3) and carpeting (2/3) and was wondering if any sort of a subfloor is recommended over the concrete slab. The room will be used primarily as a playroom for my kids and I thought that the only reason I would use a subfloor would be to "increase" the temperature of the floor itself. Thank you in advance for your suggestions.

Basements are notorious for ground moisture(vapors) coming through the foundation. Vapors cannot be seen or felt. Looks dry is not good enough.
Anything glued to the concrete is in jepordy of failure.

It being cooler in the basement, the humidity levels are going to be higher down there.

Have you thought about concrete acid staining and area rugs????
acid stained concrete (http://www.acidstain.com)

I do agree with carpets done wright. But a simple test with a 3x3 piece of plastic taped to the floor around the edges, and left for a few days, will tell you if your floor has to much moisture.. If there is no moisture under the plastic, then go ahead and install the floor. This only applies to the vinyl,, The carpet on the other hand, if you use a high quality bonded underpad, this allows the concrete to breathe.