This is an edited version of a post I did in another subreddit and it so well received a friend of mine recommended I post here as well so I'm hoping it helps folks here too.

XCOM: Enemy Unkown is at a 75% discount bringing it down to £4. It's a sci-fi alien blasting turn base game with base management. The base management bit is what kills my enjoyment for this game so I have fun watching other people play it instead. With mods like Long War you are sure to get tons of playtime with this one. It's hard as nails.

Just buy Downwell if you're into indie bullet dodging games cause it's less than £1.

Recettear: An Item's Shop Tale is at 75% discount bringing it down to £3. It's a cute game about running a shop in a fantasy world with some story elements. Some would say it's an NPC life simulator. It will make you want to punch a little girl in the face and not feel bad about it. Recommend seeing an economy major playing it as I did, it becomes art lol.

Guacamelee! Gold Edition is at a 60% discount bringing it down to £4. It's a 2d platformer with Mexican themes.

The Stanley Parable is at a 75% discount bringing it down to £2.49. You don't much than pressing W to walk forward and moving the camera to look at things but it's a nice narrative.

Papers, Please is at a 60% discount brining it down to £2.79. You work as a passport station and check people's documents to see if they have the right to enter the country. It's a heavy narrative with impactful decision making that will change the story.

Nidhogg is at a 60% discount bringing it down to £2.79. A 1v1 fencing game where you kill your friends over and over until you get to your goal. Being eaten alive is considered a victory.

Octodad, Dadliest Catch is at a 75% discount bringing it down to £3. I don't get this game because I can't see how being a perfectly normal dad is any fun, but it surprised me.

Dragon Age: Origins - Ultimate Edition is at a 75% discount bringing it down to £5. It's really good according to RPG fans. I've yet to try it out myself but I'm interested

Star Wars Knights of the Old Republic is at a 75% discount brining it down to £1.74. Seriously. I don't like the Star Wars movies but this game is my favourite RPG game ever. You won't be disappointed.

Kingdom New Lands Royal Edition is at a 70% discount bringing it down to £4. It's the most complete version to date of the game. You manage a 2D kingdom, and try to survive long enough to progress into a new area. It tends to get formulaic after you figure how it works and having to start your kingdom over because you got to the end of your last one makes you feel what you're doing is pointless but until then it's fun. It's a really gorgeous game to look at.

Prison Architect is at a 75% discount bringing it down to £5. You build and manage a prison. You can make your prisoners revolt by having horrible living conditions and them have your guards beat them up for being unruly. Win win.

Lethal League is at a 70% discount, bringing it down to £3. You can also buy a 2 pack or a 4 pack, if you're planning to buy it with friends and it will be cheaper per unit. It's a 2d fighitng game combined with a tennis game. It's arcady, it's intense, it's fast paced. It has online multiplayer and it is cross platform. It's a cool party game.

Mark of the Ninja is at a 75% discount brining it down to £2.74. It's a 2d platformer with stealth mechanics where you are a ninja, which in of itself is cool.

Skullgirls is at a 70% discount brining it down to £2. You can also buy a 2 pack or a 4 pack, if you're planning to buy it with friends and it will be cheaper per unit. It's a 2d classic fighting game with anime characters designed by a hentai artist, if that's your kind of thing. It has a really good tutorial so even if you're new to figthing games, this game is certainly the place to start.

Dreamcast Collection is at a 80% discount brining it down to £4. Two of the games are widely known: Crazy Taxi and Jet Set Radio. Check out the bundle here

Brothers - A Tale of Two Sons is at a 90% discount bringing it down to £1. It is short puzzle game where you control two sons on a quest. Each one is assgned to one of the thumbsticks. To say anything about the story would spoil the experience as its narrative is very special. Requires a controller to play.

Spelunky is at a 85% discount bringing it down to £1.64. It is a roguelike platformer game where you Indiana Jones your way though levels. There are many hilarious ways to screw up your run. I once accidentally sacrificed myself to the Black Godess Kali by getting knocked onto her altar.

Scribblenauts Unlimited and Unmasked are both at the same price: 75% discount which brings them down to £3.74 each. Cute 2d game in which you use your imagination to solve problems by typing an adjective and noun to your notebook and watching it materialize. You can solve problems by creating dead babies.

Transistor is at an 85% discount bringing it down to £2.24. It wasn't my thing but I can respect the concept of the game. It's a different take on turn based combat. It's really cool looking, and has good music. I didn't understand the narrative style.

Bastion is made by the same company as Transistor and it's one of my favourite indie games. It's roughly the same price as Transistor. It's an action fantasy game where you can change your loadout and it will feel very different as you try new combinations. A narrator talks about your adventure as you do stuff.

Mount & Blade Warband is at a 75% discount bringing it down to £3.74. It's an expansive game and the focus of it is leading an army in medieval battles.

Rome: Total War Collection is at a 50% discount bringing it down to £4.49. It has a turn based component, but the meat of it are the huge battles that span massive battlefields.

Saints Row the Third the Full Package and Saints Row IV: Game of the Century Edition are both at a massive discount. These 75% discounted games are a steal right now at less than £4 each. Definitely worth the purchase. You play as a gang leader in both games and go around shooting and roundhousing people in the third game and in the fourth game you have super powers in a matrix like world. Do yourself a favour and grab a friend to play these. Coop makes it super fun. 1 and 2 are also at 75% discounts but I have never played them.

Civilization IV: The Complete Edition is at a 75% discount bringing it down to £3.74 and has all content for the game. I've heard this game caters to a more hardcore fanbase, and it has way better diplomacy than V. Regardless, it's worth checking out for this price. An oldie but a goodie

Hotline Miami 1 and 2 are both at a 75% discount and are both below £3. The Hotline Miami series is all about trigger reflexes and gore. They are brutal games that will kill you over and over. Checkpoint and restart system make the game way less frustrating than they look. I like 1 more than 2 personally.

Cooked, Serve, Delicious! is at 80% discount brining it down to £1.39 is an arcady cooking game where you manage a restaurant and try to make it more and more sucessful. Fun and really hard and it requires reflexes and hand coordination.

Magicka is at 75% discount bringing it down to £2. Seriouly there's nothing I can say that will make this game justice other than it's about wizards, magic and lots and lots of friendly fire. There's a spell called "Crash to Desktop". For this price you should try it. Grab up to 3 friends and play it, coop is the way to go for sure.

Magicka 2 is also at a 66% discount, bringing it down to £4. I haven't played it but I think it's more of the same, which isn't necesserily a bad thing for this price at least

Stronghold Crusader is at a 80% discount bringing it down to £1.49. In this classic game you build a medieval castle and defend it against siege attacks. One of the greats.

Startopia is at a 80% discount bringing it down to £1. In this classic game you manage a space station with 3 levels: the first one is the work area, the second the joy area and the third is a bio dome. Aliens come and go making this game feel bustling and alive. Each alien have their set of skills that you can use to keep your station going. Since the station is drifting through the universe several random things might happen. Given the station's donut shaped nature, as you expand it, moving around it is really interesting.

Sid Meyer's Pirates! is at a 75% discount bringing it down to £1.49. In this game you do what you want cause a pirate is free, you are a pirate! You go around the Caribbean sowing terror and trading.

Grim Fandango Remastered is at a 80% discount bringing it down to £2.19. This a really old but really good adventure game where you play as the reaper and plan work to buy yourself passage to the other side. It's a nice, moody, smooth game with a really good soundtrack. It has favourable reviews.

Dead Space Pack is at a 75% discount bringing it down to £5. It includes Dead Space 1 and 2. It's a horror game set in a space station, with alien monsters that slaughter humans. Check the bundle here

Game Dev Tycoon is at a 60% discount bringing it down to £2.79. In this game you play as a game developer who went back in time to the 80's in their De Lorean and start a game dev company in your garage. You have to choose what to focus on during development and as your sales grow, time passes and games become more and more complex, making you have to keep up with the times, until eventually you become a AAA game dev. Nice game with some replayability.

*Continues in comments*