LDG-Gaming

Other things:

Divinity 2 and its add-on Flames Of Vengeance for 9.99€ at Gamersgate (no software needed to download it),
Duke Nukem Forever for 3.74£ (4.50€) at GMG (Steam needed),
Vampires The Masquerade: Bloodlines for 5€ on Steam,
and the Steam weekend deals which are Saint's Row The Third for 25€ and Saint's Row 2 for 2.50€ (!) and Payday: The Heist for 9.50€ (you can try the latter for free this weekend).

Here some Game for free:

The Elder Scrolls 1 Arena and The Elders Scrolls 2 Daggerfalls. But you need Dosbox to play the Games.

New deals:

-75% on all Deus Ex games at Gamersgate, i.e. the 1st for 2.50€, the 2nd for 2.50 and Human Revolution for 12.49€ (DLCs are also cheaper). There is also Deus Ex Collection with all Deus Ex games for 22.49€.

Mass Effect 3 for 34.99£ -20% with the code TAKEE-ARTHB-ACK20 at GMG, i.e. 28£. (Origin needed!). Also on Alienware's website, if you create an account, you will get an exclusive weapon. The number of key given is limited, so hurry up if you're interested!

If you like city builders, Civilization V is priced 4.99£ at GMG, instead of 19.99£.

On Steam:
If you like football (soccer, if Americans read me ), you will find Football Manager 2012 for 19.99€/7.99£/11.99$.
There is also -66% on The Sims 3 i.e. the game for 15.29€ and it also applies on all the DLCs. (If you buy all the DLCs you will pay... 111.40€ )
Then, you must buy the pearl that is Psychonauts for only 4.99€/2.99£/4.99$. This game is one of the best I've played, with a unique ambience and original gameplay mixing action, platforms and telekinetic powers.
If you prefer RPG, there is Two Worlds 2 for 12.49€, 19.99€ with its add-on "Pirates of the Flying Fortress".

If you prefer RTS, and harcore ones, you should try Wargame: European Escalation for 12.99£ (or 10.99£ with the code "pcgamer20") at PC World ( I don't know well this website so I don't know if you'll have to use a software to download the game or not). It's made by the developers of R.U.S.E. and Act Of War, and it's centred on micro-management (like check the supply lines, that your vehicles have enough fuel... that kind of things).
( It only works in the UK, you can't buy it from another country )

$5.49 for a copy of the Unreal Anthology, which comes with a non-pirated copy of ut2004. Personally it's the cheapest I've ever seen for the Anthology.
http://www.amazon.com/Unreal-Anthology-Pc/dp/B0022NHOP2

Another wave:

On Steam, L.A. Noire for 14.99€/14.99$/9.99£ (DLCs are also cheaper and you can have the complete edition for 5 more "eurodollarpounds") and Orcs Must Die! for 3.49€/3.74$/2.99£ (it's a tower defense).

On Impulse Driven, among others there are:
Batman Arkham City : 18.98€
Batman Arkham Asylum GOTY : 7.59€
Saint Row 3 : 24.99€
The haunted : hells reach : 2.49€
Dead rising 2 : Off the record : 14.99€
Rage : 24.99€
Amnesia : The dark Descend : 4€
Call of Cthulhu - Dark Corners of the Earth : 9.99€
Fort Zombie : 1.99€
Resident evil 5 : 9.99€
(go to the "On Sale" tab or search the game you want in the search box)

On GreenManGaming, Dungeon Siege III for 8.74£ (Steam key)

On Amazon.com, Battlefield 3 for 29.99$ and its DLC Back to Karkand for 7.49$.
Also there is a "Game Downloads Deal of the Week - Ubisoft DRM-Free Games: Buy One, Get One". Buy a 5$ game in te list and get another one for free! (I'd advise you the Splinter Cell series and Far Cry (at least the 1st)).

On Game.co.uk, Heroes Of Might And Magic VI Collectors Edition for 9.98£; they send you a box with a real CD and extra stuff since it's the collectors edition, and shipping is free in the UK!

Finally, you can try Star Wars: The Old Republic for free this weekend! (from thursday to monday)

It never stops:

On GMG, Assassin's Creed (the first one) for 3.99£.

On Gamesplanet, CoD Modern Warfare 3 for 26.79£ (Steam key).

On THQ, Lots of series for 5$ or less such as Company of Heroes, Homefront, Red Faction, Metro 2033, Supreme Commander, Titan Quest, Warhammer 40k - Dawn Of War - Dawn Of War 2 (this one costs 10.80$), Saint's Row 2; Saint's Row 3 is at 24.99$.

Let's keep it up:

On Gamersgate, Battlefield 3 for 19.98£ (24€) (Origin key)

On ShopTo, Saint's Row the Third for 9.85£ (12€) (Steam key) and also Need for Speed The Run for 19.85£, FIFA 12 for 19.85£, Homefront for 9.85£, Deus Ex: Human Revolution Augmented edition for 9.85£

On Steam, Midweek Offer:
Portal 2 for 9.99€ (-50%) http://store.steampowered.com/app/620/
Portal 1&2 for 12.50€ http://store.steampowered.com/sub/7932/
Total War: SHOGUN 2 for 10€ (-75%) http://store.steampowered.com/app/34330/
Le DLC Total War: SHOGUN 2 - Rise of the Samurai Campaign for 1.75€ (-75%) http://store.steampowered.com/app/34344/

Daily Deal:
Spellforce Series for -75%
Spellforce - Platinum Edition for 2.49€ http://store.steampowered.com/app/39540/
Spellforce 2: Gold Edition for 3.74€ http://store.steampowered.com/app/39550/
The pack including both for 4.99€ http://store.steampowered.com/sub/7475/

And because I enjoyed a lot Portal 2, a nice parody:

A huge wave of good deals on Amazon.com:

Crysis 2 - $7.49 – Activates on Origin

The Darkness II - $12.49 - Activates on Steam

Dragon Age Pack (Dragon Age Origins Ultimate+Dragon Age 2) - $9.99 - Activates on Origin

Kingdoms of Amalur - $39.99 - Activates on Origin

L.A. Noire - $4.99

Major League Baseball 2K12 - $19.99

Mass Effect 3 - $49.99 - Activates on Origin

Serious Sam 2 - $2.99 - Activates on Steam

Serious Sam 3: BFE - $11.99 - Activates on Steam

Serious Sam Double D - $2.39 - Activates on Steam

Serious Sam HD: The First Encounter - $4.49 - Activates on Steam

Serious Sam HD: The Second Encounter - $5.99 - Activates on Steam

Serious Sam: The Random Encounter - $1.49 - Activates on Steam

Shift 2 - Unleashed - $4.99

Syndicate - $39.99 - Activates on Origin



Other Awesome Deals (Sorted by Price):

$12-$30 Deals:

Call of Duty: Black Ops - $29.99 - Activates on Steam

Cities in Motion Collection - $11.99

Crusader Kings II (Only good 4/5-4/8) - $17.99 - Activates on Steam

King Arthur II (Only good 4/5-4/8) -$17.99

Mount & Blade Bundle - $14.99

Paradox Deep Sea Collection - $11.99

$6-$10 Deals:

ArmA 2 - $9.99

ArmA 2: Operation Arrowhead - $9.99

ArmA2: Combined Operations - $9.99

Commander: Conquest of the Americas - $5.99

Defenders of Ardania (Only good 4/5-4/8) - $6.74 - Activates on Steam

East India Company Collection - $5.99

Hearts of Iron III Collection - $8.99

Magicka Collection - $5.99 - Activates on Steam

Majesty Pack - $8.94

Rise of Flight Iron Cross Edition - $9.99

Ship Simulator Extremes - $5.99

Stronghold 3 - $9.99 - Activates on Steam

Sword of the Stars: Ultimate Collection - $5.99

On GoG, you can have Fallout 1 for FREE! (and DRM free).

A while ago, someone asked for discounts on Magic The Gathering 2012 (I think it was Paladin (!)); there it is on Steam for 6.79€/6.79$/5.09£ (this price is for the complete edition).

And if you feel nostalgic, all the Might And Magic are 3-5$ on Good Old Games. (Buy the 3rd!!!)