Harmony 3-in-1 Premium Underlayment is the top of the line laminate flooring underlayment and is perfect for basement laminate floors as it seals out moisture while giving it a chance to breath and push the moisture out the sides instead of trapping it.
Home Depot sells the stuff for $60 for a 100 square foot roll, but the web has that beat. You can buy a 630 square foot roll on Amazon for $210. That's more than $150 less than it would cost at Home Depot and it ships for free with Super Saver shipping. Just plan ahead!
The underlayment is made of 3 layers - with a specially designed middle layer made of little styrofoam balls. You lay the stuff down quickly and this stuff has a really nice 7-inch overlap layer that helps seal the floor from the bottom all the way across the seams.
I'd recommend this underlayment to anyone - especially if you're looking to lay laminate floor in the basement where there is bare concrete floors. I wouldn't however lay this stuff - or any floors in the basement for that matter - without having your basement waterproofed first. That's your insurance policy.