I own a Surefire L2.  It's an awesome light, I use it every day.  It has great regulation, and it's BRIGHT.  It will completely illuminate a dark room, and outdoors at night it is amazing at close-medium range.  At those ranges it illuminates things better than my car's high beams.  It's also built like a tank, very durable and waterproof.  It's seen a great number of falls and some pretty hard use, and the most that has ever happened has been a few small scratches - nothing that would ever affect its performance.  I have to say I highly recommend this light.