Favorite concrete screw?

[Greg R Bradley]

Tapcons are OK but GRK Caliburn are simply the best I've seen.

[David Helm]

Are you dead set on screws? Along with the powder actuated fasteners already mentioned there are also drive pins. You will need a roto-hammer with a 1/4" bit. I've been out of that part of construction for a while but we used to use drive pins all the time. There was also a duplex head drive pin available for potential removal.

believe what you are talking about are called split pins around here. In my opinion they are the best choice for pinning a wall to a floor.
I