Yeay, Steam is a thief: Once they have stole customers with expensive price for some downloaded games, they steal developpers with ridiculous prices.
Just don't buy at Steam: they are DRMs.

Are you sure you don´t mean the old X-com games? I can only see UFO: Afterlight on STEAM and that costs 9,99€.

wait what? what's the difference?
I got 5 games of a weekend deal

Not the same games.

The five games of the original X-Com series were published between 1994 and 2001.
The two UFO games on GOG are not part of that series and were published in 2003 & 2005.

I don't believe the X-COM games on Steam have any DRM. I bought them all there in a weekend deal too and the ones I've played run without Steam running.

You need Steam to install them, once downloaded. We don't need GOG to install downloaded GOG games. Once downloaded, GOG games are ours, we FREE install them when and where we want, we don't have to ask GOG every time to install them. And yes, Steam games may need internet just to be played: NEVER GOG games (else multiplayer ones for sure).
Just read Steam forums threads on many forums on the web: You will laugh about all their problem, waiting for weird patching, waiting for Steam servers are up just to play a solo game, guessing how to install a mod, stolen accounts, etc...
What is funny is Steam fanboyz hate the last Ubi drm... Steam should have prepare them for it!

Sigh, if only the X-com series was on here. If GoG.com really puts as much as they do into patching games, I would love more than anything for X-com:UFO to be patched for windows vista or 7 without having to do anything weird to make them work. Still today, the best strategy game I have ever played. Challenging in a way that it doesn't seem overwhelming unfair.
Speaking of which played afterlight, that was a good game but it had some SERIOUS performance problems. Something about leaked memory but also a good mod community for awhile. Anyway. good game. I've never tried these ones.

You should check up on offline mode, it basically invalidates a couple of your claims alone.

Offline mode makes no difference to gamers like me who simply cannot accept the Steam eula.
I work for a highly prized commodity known as money and if you read the companies stance on you having anything of value for your hard earned dollars you'd realise you're better off putting your wallet through a wood chipper placed over a lit fire-pit rather than dealing with them.
Personally i hate the idea of auto patching becoming the norm for games.
Sins of a solar empire has it (which i bought due to them advertising it as having no DRM) and because i refuse to install impulse which 'is not software pertaining to the actual game' i am left with a product of reduced functionality simply due to the fact i need to access their 3rd party steam like program for patching in order to maintain the ability to use multiplayer.
Needless to say a good $80 game is now sitting on my shelf uninstalled with no resale value and no value to the customer 'me'.
So forgive me for saying it, but WELL DONE GOG!
The only thing they need is more content and a few more recent games on their list though the way things are going in the gaming industry at the moment the latter is not looking likely.

While Steam is not my favorite distribution service, and many of the complaints here are valid, it should be pointed out that games using dosbox that are sold on Steam do not use Steam's DRM. Aside from needing to use Steam as a download manager, your use of these games is no more restricted than if there were from GOG.
I copied my steamapps/common/x-com folder to my linux-running laptop, and happily launched dosbox using the Steam-provided dosbox.conf.

But you must beware not to let Steam see your moded games, as moding is forbiden by the EULA and Steam can ban your account.
Yes, if mods are no longer allowed, you'll have to remove them or loose your games.
GOG does not and can't spy what you do with your owned games.

That's news to me; I have an HL2 mod installed (which even shows up in the Steam games list), about a dozen Fallout-3 mods, a couple of Witcher mods and about half a dozen mods for Torchlight.
Interestingly, Fallout-3 doesn't seem to have any DRM in Steam either; on my PC I can run it from the install directory regardless of whether Steam is running; I actually have to run it that way because Windows Update screwed up the .Net Framework so I can't run the Fallout-3 launcher from Steam.

That is pure and utter bullshit. Only the exe file shouldn't be modified (some games will still allow it though, especially older games like X-COM), and if you do that Steam will simply re-download the original exe file.

Steam even encourages the use of mods for Valve games, by hosting some of them in the Steam store.