I've resisted the temptation of getting a laser level... I've had a water level for about 25 years that I've used for leveling buildings, leveling floors, leveling ceilings, installing cabinets, building decks, hanging exterior siding, setting fence top levels, and for setting grade levels for driveways, yards, retaining walls, foundations, etc.
I've got it filled with blue colored automotive windshield washer fluid so I can see the water level easier and so it doesn't freeze. The batteries are never dead, it only takes one guy to operate, the worse case scenario for dropping it is having to add more washer fluid, you can set levels outside line-of-sight (I've hung the water bottle inside the house and marked level references on the all the outside walls of a house by sticking the hose through window and door openings), and it was and is cheap. The one I have uses water only, no electronic gizmo to bust or have dead batteries!
John Who cannot justify an electronic gizmo when water works just fine... ;~)