My preference (having fitted c/ls for a few pilots) is a soft lens made out of Silicon Hydrogel material, most of these lenses are suitable for overnight wear and can be resistant to drying out.
Bausch & Lomb Purevision, Coopervision Biofinity, CibaVision Night & Day are all examples of this type of lens ( there are others on the market as well).
Another material that works well especially if dry eyes are a problem is Coopervision's Proclear, but it is not really suitable for overnight wear.
As with all internet advice see your eyecare practitioner for definitive advice.