My prefernece is a simple disk check, it's pretty straight forward, just install the game, and as long as you have the disk, you can play. No need for online registration or third part programs that should be unnecessary with features I'll never even use, or any of hat nonsense. It's the most convenient, least intrusive form of copy protection available for the player.
Although Steam is still preferable to Ubisoft style DRM or limited installs or whatever, but I'd also rather be punched in the chest than kicked in the groin, I'd still prefer to not have to deal with either one, though apparently Bethesda doesn't care that some players feel that way.
I can see it being somewhat of an issue with people who don't have reliable internet, but you can solve that issue by simply running Steam in offline mode.
I have a reliable internet connection (hence why I can post here regularly.) but I still don't want to have Steam forced on me.