Which of the following is the best DRM in your opinion?

[Zkuq]

twesterm said:

Zlejedi said:

Steam is also extremly restrictive DRM system but at least if you are paying 5-10 euros per game it won't hurt badly if you lose access to it.

I'm confused, how is Steam restrictive?

Must be logged in to play games, at least initial online activation, can't resell games. I think that's the most important parts.