My sewing rooms have always been in the basement. Concrete floors aren't the best on the legs - mine get achy mighty quick right now, as carpet hasn't been laid yet. Carpeting adds warmth to the room, and keeps it from sounding "hollow", as pergo and laminates do. I love carpet in my sewing rooms. We don't have water problems in our basement, so no worries there.
I found these carpet tiles at Home Depot
http://www.homedepot.com/p/Versatile...T001/203051709 and fell in love with them. As far as I'm concerned, it's like having a scrappy quilt on the floor! Added bonus, they're 2x2 feet, so if you've got to lay out a quilt, you've pretty much got a built-in ruler. They've gotten rave reviews on the site, and there are tons of pics that people have posted in the reviews. The floors look fabulous. At $1/SF, you can't beat the price. I was blessed with a large area in this basement - about 480 SF, so $500 to carpet the room sure beats the $1500-2000 it was going to cost! I'm going to buy an extra box for those moments when I spill glue, paint or other assorted liquids. Just peel up the square and lay a new one.
I've emptied out my sewing room (except for the LA machine, which still has a quilt on it) and DH is going to start painting the cinder block walls this weekend. The carpet tiles are on order! I'll post a pic once it's finished