Two Dumb Things

My least favorite head for a screw is a straight slot. As long as your screwdriver fits well it works OK but if you get in a hurry it's easy to strip it. I would put phillips a step better but without adequate pressure it can strip or get chewed up and not work. I put allen heads after those two. I agree torx are a bit more dependable but I think allen heads work pretty well.

I mostly use some "Huskie" allen wrenches from Hope Depot. I also have some fairly long metric allen head bits to got in a 1/4 allen head screwdriver.

I don't usually use the wrenches that come with my guns or related purchases but I also don't usually throw them away. The go in a drawer somewhere just in case I ever want them for something. I needed a short one recently, for instance, and could have cut down one of the freebies.
 
1 - DON'T...use cheap Allen wrenches...period.
2 - DON'T mix Metric and SAE wrenches.
3 - Be sure that you insert the wrench...properly/fully into the socket before you twist the wrench.

That way, your screw head sockets will normally remain in good condition.

Mike
One more thing for the list.
DON’T over torque the fastener.

I would bet thats number one or second reason next to bad allen keys for the cause of stripped allen heads.