Which games worth to buy from the current promos ?

Please DO NOT RECOMMEND DOOM (2016)

Thank you .

Well, you have a ton of games that are considered classics, and it all depends on your preferences, of course.

Here is a list of games costing less than €10.

If you love first-person shooters

DOOM + DOOM II
F.E.A.R. Platinum
Quake
Quake II

Turn-based strategy games

Fallout (classic)
Heroes of Might and Magic
Heroes of Might and Magic II
Heroes of Might and Magic® 3

Jagged Alliance 2
Jagged Alliance Deadly Games

X-Com: UFO Defense

Management games

Dungeon Keeper Gold
RollerCoaster Tycoon® Deluxe
Theme Hospital

If you like builders/management games:
Terraformers (€9,99) - I'm currently playing this, and in love. An amazingly well realized blend of 3X/city builder with some roguelite deck builder concepts thrown in to limit what you can build.
Urbek City Builder (€5,59) - yet another twist on the city building genre; this one is very puzzle like, since entire neighborhoods evolve through the presence of facilities within a certain distance.
Transport Fever 2 (exactly €10) - it's not quite OpenTTD, but scratches most of the same itch, and looks gorgeous.

Gurumin: A Monstrous Adventure

Check it out. I got it on sale and it's worthwhile.

It would help to know what type of games you enjoy, but here's a few I enjoy from my own GOG library. According to Google, the price these are listed at in US Dollars is less than 10€, but not being in Europe, I can't guarantee that to be accurate in every case for the pricing on GOG. I know it's not always a direct conversion at the current exchange rate...

The majority of the games I'm including here are getting a little old, because my computer is positively ancient and can't play most games made within the last ten or so years. But I'm only looking at games from my GOG library that I have personal experience with, and that fall into your price range. :)

City Builders/Strategy Games
Banished - Lead a small group of people banished from their homeland to create a city that provides for their every need. The only enemy in this game is time, as in, can you get food and supplies going in time to prevent your people from dying off.

Ozymandias: The Bronze Age - This one is kind of a Civilization Lite, or maybe if you made Civ into a much more basic tabletop game (and yes, I know there's a Civ tabletop game, but I know nothing about how complex it iis). It takes a little bit to get used to (the tutorials help a lot) but I've had a lot of fun with it.

Tropico 4 - Possibly the best entry in the Tropico series. Rule a small Caribbean island and decide what to build and what to base your economy on! It's up to you whether you're a benevolent leader or a dictatorial monster. This is the game I'm currently burning multiple hours per day playing.

Pharaoh - This one's pretty fun; you rule Egypt and build a city complete with shops, temples, and monuments. The pathfinding of your citizens is a little screwy sometimes though.

Galactic Civilizations II - This one's old enough now that you can get the Ultimate Edition, which is the complete game, for just $9.99. I've had quite a bit of fun with it; if you like the idea of Civilization in space, this is a good option. Stellaris and the later games in the Galactic Civ series are considerably more expensive, especially if you want all the addons and DLC.

Railroad Tycoon II - This game is pretty old at this point, but it remains one of the best freight transport sims out there. There are newer games that attempt to fill the same niche, but none of them do it as well as RT2 does, and some of them have some major problems, like really screwy pathfinding.


Role Playing Games
Divine Divinity - This one is an older RPG, and I can't say a whole lot about it, since I haven't gotten around to playing it all the way through yet. What I have played though, I have quite enjoyed, and I am looking forward to playing it and some of the other games in the series when I get over my current Tropico 4 phase.

Eschalon Book I - This one is a really old school adventure RPG, and it has the distinction of being the cheapest game in my list - it's FREE! It's not much to look at graphically, being so old school, but I did enjoy playing through it last year. If you give it a try and like it, you can have Book II and Book III combined for less than your price limit. :)

Dragon Age: Origins - This is possibly my favorite game from this list. It's getting kind of old now, but it's one of the best entries in the Dragon Age series, maybe even THE best. Be forewarned, though, when it got added to the GOG Preservation Program recently, GOG made some changes to the installers that kind of broke it for a lot of people. If you go for this one and you use GOG Galaxy, you might have better luck with one of the older versions of the installers.

DOOM (2016)

He said exactly don't recommend DOOM (2016), probably bought it, played before or not interested, :)

Without saying what sort of games you're looking for, this is casting a very wide net and will turn into a list of personal favorites...

But all right, let's see...

The original Age of Wonders trilogy. 1, 2 and Shadow Magic
Arcanum
The Bard's Tale (2004) (no idea how the remaster is)
Betrayal at Krondor (sold together with Betrayal in Antara, no idea about that personally)
Gothic 1 and 2
Heroes of Might and Magic 4 (unpopular, I know)
Homeworld 2 (personally played that first and then couldn't deal with the immobile mothership in 1, so I gave up on that almost as soon as I started it - also, no idea about the remasters, but originals are included)
King of Dragon Pass (no idea about the new version, but the old one is included)
King's Bounty: The Legend
Septerra Core
The Settlers 2
Tropico 3
Two Worlds (just the first one, yeah)
Vampire: The Masquerade - Bloodlines
Worms: Armageddon

The Elder Scrolls IV: Oblivion, The Witcher, Jagged Alliance 2

Thank you for mentioning this. I looked at Goblinz games before, but the name of the game didn't make me click on it and check it out. Now I did. Might be something I'd enjoy.

Games I've played and recommend:

Fallout series, mostly New Vegas
Deus Ex series
SWAT 4 if you like to play horror games disguised as tactical shooters
World In Conflict
Far Cry 2
Doom 3, which comes with BFG Edition which comes with censored versions of the first two Doom games plus No Rest For The Living which is a pretty tight WAD.
Turok if you like Doom but with metroidvania-lite elements.
Crysis
Soldier of Fortune II, but a shaky recommendation since it's a pretty good shooter that's a bit too flawed for a curiosity purchase. It's more of a "trust me bro" purchase at best for its price.

Try MOTORSLICE, you can see the protagonist, P, in the promotional image probably provided by Top Hat Studios on the home page. Oh, hang on a minute, that game isn't currently available on GOG (It's not even out, full stop). Disregard...

Many of the Steamworld games are 85% to 90% off and are great games with a wide range of genres with a slightly interconnected story since they all happen in the same universe.

The Steamworld Dig series is a great exploration games allowing you to dig through caverns finding loot and gear to upgrade your character to continue digging to find the prize hidden deep within the ground.

The Steamworld Heist series are 2D turn based tactical strategy games with plenty of maps and planning to take out enemies and survive. The first game I feel is the better of the two.

Steamworld Quest is a card/deck style RPG that happens in a more fantasy setting.

Steamworld Build is a city builder style game but did release with some controversy due to the EULA they released with it. Probably the weakest in the series.

Alan Wake - if you like Max Payne, Twin Peaks or just want a great supernatural thriller.

SWAT 4 - one of the best FPSes I know, insanely replayable too,

Robin Hood Legend of Sherwood - probably my favourite "Commandos-like". Very nice graphcis that still hold up, good voice acting, clever implementation of just about everything you'd want from a Robin Hood game - archery, ambushes and traps, swordplay, growing your band of merry men and Sherwood hideout etc.

Star Trek games: Away Team, , [url=https://www.gog.com/en/game/star_trek_voyager_elite_force]Elite Force - if you're a Star Trek fan, these are absolute must plays. Even if you just kind of tolerate Trek, you can give them a shot, as they are very solid examples of their genres.

Chains of Satinav - one of my favourite point & clicks of all time. Great story, solid puzzles (needed no walkthroughs, but didn't feel too easy), wonderful graphics, it almost has the feel of some lost fantasy movie from the 80s.