its easy to buy games, you dont have to get out of the house.
it saves spaces because no discs are needed anymore that get dusty.

your updates are always the newest, you dont have to look for new updates, its all automatic.

a lot of games are listet. everyone will find something there.

Support is not one of the things.

What I like most: that it's cheap and convenient
What I hate most: that it's cheap and convenient... and I end up spending way too much.

Huge discounts :)

Numbers 1 and 2 on the OP ;)

That it's not Origin

achievements. i fucking love achievements.
And that i have all my achievements in one place

Most of my games are in the same place and they're always backwards compatible.

I'm surprised noone mentioned this.

Cube World

Able to conveniently sort and download/install most of (if not close to all) my games from one convenient source. Able to play the same game on multiple devices through cloud save-game sharing. Easy access to play with friends (on common platform), quick download and close to no errors at all (never had more than a few single incidents throughout my 7 active years of using Steam. In my opinion the best "DRM" (citation marks since I don't see it as much as DRM but more as a simple library) 'non-brand-bound' online game service provider.

I like the fact that if I feel like playing some game, I just start downloading it (well a lot of platforms hace this feature but that's just one of the things Steam has to offer), and I like doing that quite a lot. :)

simple, organized, sales and lots of games

The high number of cheap/free games you can't get from bundles and so on.

3 market, trading and greenlight (community)

sales about it.