The Marmot Mavericks 30 is an all synthetic bag that has the most unique features of the bags we tested. First, the semi-rectangular shape creates a lot of room, but saves weight by tapering from head to foot. An additional half length zipper lets you completely fold down the top torso portion of this bag. This is great in warm weather, and also when you want to sit in a chair and read a book while wrapped up. The warm back of the bag can be behind you while the front folds into your lap out of the way.
The luxuriously warm and comfortable Slumberjack Country Squire 0, our Editors' Choice winner, is the best general-purpose rectangular sleeping bag for cold weather. Our Best Buy winner Kelty Callisto 30 is more versatile for warm weather, and could also be used backpacking in a pinch.