I haven't done much gaming for a while, what are your favorite games from the last few years?

Got any must haves / good recommendations?

Help.

My suggestion would be to grab only one or two games right now and then wait on the summer sales on steam and gog.com. Then you will have more games than you know what to do with and you'll be making a new thread asking what to play first. If you want a specific game The Witcher 3 game of the year edition is on sale on gog right now for 20 bucks which has hundreds of hours of content or a game I've sunk a lot of time into on PC is Rocket League. Welcome to PC gaming.

Doing a majority of your shopping during the upcoming digital distro sales is good advice, not least because Steam, at least, is a miasma of garbage, and trying to find anything beyond what's on the main page in the store is nearly impossible. It's actually better during their sales, because they usually reformat their main page to highlight more stuff, and have better grouping by pricing, etc.

As far as suggestions for the short-term, that's tough without knowing your preferences in games. I'd definitely try to find something that just makes you say "wow, video games look like this now?!?," because one of the obvious advantages to PC gaming is the power. The Witcher 3, Doom, Battlefield 1 (only available on Origin), or Assassin's Creed: Origins would fit that bill nicely. Beyond that, though, try out some games that just don't work well on other platforms, such as Civilization. I have not played Civ VI, but have lost many a night to Civ V. You can probably get the latter pretty cheaply even outside of seasonal sales, given it's age.

Witcher 3, Assasins Creed Origins, GTA V.

There's a lot to choose from and you haven't said what types you like? As Bedouin said, you can build up a decent stack of games from Steam, GoG or Humble Bundle.

Games I've liked have been:

Funny: Jazz Punk, The Stanley Parable

Action: Just Cause 3 is always good for a laugh, you can grapple onto virtually anything and just blow stuff up, it's fairly cheap now too. Hitman, Syndicate and the recent Tomb Raider series are good, or you could just go the PUBG/Fortnite route I guess.

Strategy: Invisible Inc seems fun, although I haven't got far yet. If you want suggestions that aren't obvious, then two Kickstarter games I backed were funded and completed - Satellite Reign (an early 90s Syndicate clone, not the one I mentioned above), and War For The Overworld (see the PC version of Dungeon Keeper, not the trashy EA mobile version). Both games have heavy roots in the games that inspired them, they just pushed out a major patch for the latter to include new features, but they've really done the job well in terms of aftercare and it's been a full game for some time.

Racing: Formula Fusion - another game that I backed and was finished. It's basically WipeOut and some of the original devs worked on it. Grip which is Rollcage, and Dirt Rally which is awesome as a version of Dirt without all of the silly menu stuff which plagued the previous games, and it feels good.

Puzzle: Contrast, The TALOS Principle, Hexcells

Sim: Kerbal Space Program

That's not even all the categories (I don't play MMOs for example), but those all have a quite a few months since their release and you could probably pick them up without hurting your wallet after buying a PC, even cheaper on a sale.

Edit: Oh yeah, shit, I forgot about Doom and Rocket League. I have The Witcher 3 but haven't made a dent in it yet, I've heard it's good though.

Obligatory Far Cry and Crysis post.

How long is "the last few years"? Like, the beginning of this console generation, or like, two years ago?

Anyway, sure, I'll list off a few of my personal favorite games from the past few years with a short description. I strongly approve of any one of these games.

• Shovel Knight - 2D throwback action platformer, Mega Man/Castlevania-esque in a lot of ways. Hardly the thing if you're looking to stretch your computer's limit, but I've had a ton of fun with this game and it's expanded quite a bit with free DLC since release.
• The Witcher 3 - You'll probably hear this one a lot. It has kinda become the gold standard for fantasy RPG writing since release. It has its detractors, as does every game that gets mentioned in like half of today's video game forum posts, but you need to play it for yourself. Also, even though it's a 2015 game, it's still a good benchmark for your PC, and still looks jaw-droppingly gorgeous in some areas. Novigrad - while not my favorite area in the game - needs to be seen if you haven't been playing video games for a few years.
• Dark Souls III - Dark Souls got pretty big in 2011 and the franchise has only gotten bigger since. Dark Souls III is supposed to be the last one that From Software is going to make and they sent the series out on one hell of a high note. If you know anything about the Dark Souls I PC port, you know it's a real bad port, but DSIII's port is pretty good as long as you're playing with a controller.
• Doom 2016 - Do you like 90's first person shooters? OK, good, play this game. Excellent design, all-around. Extremely fast-paced, extremely gory, extremely fun. Like The Witcher 3, this game seems to get mentioned in roughly half of today's gaming forum posts, so there are a few people who will pipe-up and say they don't like it. Also like The Witcher 3, it goes on sale frequently and you can get it for a pretty good price if you keep an eye out.
• Prey 2017 - Has nothing to do with the old Prey that was released in... 2007, I think? Anyway, Prey 2017 is best summed up as "the System Shock 3 that we never got". It's very System Shock-y or Bioshock-y, depending on your point of reference, and it's a damn good game in that vein.
• Dishonored 1 and then 2 - Do you like Thief? What if Thief had magical superpowers granted to you by an otherworldly god-like presence? Dishonored 1 and 2 are that, but with some of the best and most creative level design I've ever seen in video games, especially Dishonored 2.
• Wolfenstein: The New Order, Wolfenstein: The Old Blood, and Wolfenstein: The New Colossus - Just as The Witcher 3 has become a benchmark for writing in RPG's, these games have become the benchmark for writing in first person shooters. Most people never thought that BJ Blazkowicz would wind up being perhaps the most relatable and human meathead ever, but here he is, and he works with a varied and interesting cast of great characters. Lots of style in these games, and lots of crazy moments, but the gameplay of both games isn't so universally praised. I liked the gameplay well enough, but if you're not having fun shooting things, then it's still worth bumping down the difficulty and experiencing the story beats and moments.

Anyway, you may have heard of all of those, you may not have, they've all been talked about quite a bit over the past few years, but I don't know how out of the gaming loop you've been so I just tried to think of some highlights.

DmC for solid character action (should be played with controller)

Warhammer: Total War for what is now a very solid battle experience

Titanfall 2 for arena-tempo shooter with a solid campaign

PUBG for tense survival-shooting

Ori and the Blind Forest for an atmospheric delight with decent platforming (played best with controller)

Oxygen Not Included for a podcast/video watching game

Witch3r, DOOM, Hitman.

Damn there's been a lot honestly. Limited to PC?

DOOM for sure, it's my favorite first person shooter in a looong time.

Witcher 3 is maybe the greatest open world RPG ever made. I'll fight for that.

Hitman is fantastic if you are into that kind of thing.

NIOH is a great but very difficult hack and slash game with loot.

Metro Redux maybe if you haven't played them? They are good showpieces for a powerful PC.

The new Tomb Raider games are pretty good.

If you like classic RPGs like Baldurs Gate, then Pillars of Eternity and Divinity: Original Sin 2 are both great.

MGS5 is also a nice sandbox stealth/action game with a ton of content. Story is uh. Something.

We probably need an idea of what you're into or what sort of thing you're looking for.

Pillars of Eternity and DOOM are both brilliant, but completely different.

Since you built a new PC I assume you want something that looks great. If your in the mood for a fighting game Injusitce 2 is a good one of those with a sizable amount of solo content. Everyone else has already mentioned any other game I might mention from that point of view. But if you happen to be looking to play a 2D metrodvania then Steam World Dig 2 would be a good choice since the movement in that game is amazing.

Unpopular opinion: Fallout 4 with mods, unless you're a story > gameplay person.