It depends on the application.
If it is a prolonged job in stationary area I usually like the work light. Examples would be installing a sink in the cramped quarters of an RV bathroom where I will wrap a gorilla light around a pipe or something. Or installing a woodstove insert where I am laying on my back working overhead while wearing safety glasses, face shield and dust mask.
Other jobs I find the headlamp to work well, such as cleaning the gutters on the house and shop in the dark, or changing a hydraulic hose on the excavator in the dark.
In some cases both a headlamp and a work light are needed. For example, changing a part on the engine in the dozer where I use the work lamp for general area illumination (like the surface where my tools are laying) and the headlamp to illuminate the specific part/fasteners I am trying to remove/install.
And finally, we use the light tower to provide large area illumination such as doing machine work (excavator/dozer) in the dark, or bucking up logs and splitting firewood in the dark. Mending a section of fence after dark etc.
This is my favorite headlamp. I only use the type of headlamp that have the center strap over the top of the head because I find they stay put much better during hours of use, especially if I'm sweating a lot. The single strap models tend to shift when you adjust the tilt of the beam, and they slide down on the head.
Other important attributes include a well diffused beam. It's great to have 6,000 lumens of brightness but if it is not a quality, well diffused beam then it can be next to useless. Also, a large range of motion in terms of vertical tilt of the beam is important. Nothing like burying your chin in your chest trying to get the light low enough to be on the subject, or cranking your neck all the way back to get the light on the object. And finally, large buttons that are actually useable with gloved hands.
http://www.amazon.com/dp/B0018KS364/?tag=atomicindus08-20
This is my favorite battery powered small worklight. It is some sort of no-name cheap China model that I find very useful. It has a wide base and having the batteries in the base make it very stable. The head has good range of motion and it has a very wide beam. It has a very large on/off button that is easy to use with a gloved hand.
I really wish I could find a quality version of this design, or some thing close to it, because I will eventually drop this thing and it will be done for. A couple years ago I bought a stanley tripod light but ended up returning it as the quality and function were just not acceptable.
Light towers make large area illumination possible.