Vapour barrier? No - I would think that would trap the moisture and actually cause more of an issue than anything.
I used Barricade 2x2 tiles which have a foam underlay and an R value of 3.2. Now that my basement is done, they were the greatest investment in the entire process. Carpet feels great, doesn't feel like you're walking on concrete, no musty smells and the temp is amazing.
http://www.rona.ca/en/insulated-r32-...3-1-4-01925002