The ALPS Crescent Lake 20 is the warmer of the two 20 degree mummy style camping sleeping bags we tested. While rectangular bags are more roomy and comfortable than mummies, some folks choose an affordable synthetic insulated bag for general use. The mummy shape is more thermally efficient, and the hood means you don't need a hat for cold nights. The Crescent Lake's insulation doesn't compress as well as some others, but it is one of the two lightest bags in this category.
The other 20 degree mummy, the Mountain Hardwear Bozeman Flame, is a just a little roomier than the Crescent Lake, but not as warm. The Slumberjack Country Squire 0 is the warmest and most comfortable general use bag we tested. With premium features, it wins our Editors' Choice award. The Kelty Callisto 30 won our Best Buy Award; it is competitively priced, roomy enough to be plenty comfortable car camping, and light and versatile enough to go on short backpacking trips.