Divinity Original Sin: This is a wonderful content rich turn rpg that manges to combine old school turn based party combat with modern graphics and a lovely bright aesthetic. I have over 130 hours played and still plenty more to do in game.
Civ V (again): Despite having 70+ hours in game I don't think I have every finished a full campaign of Civ V but it is a perennial classic that warrants revisiting over and over again.
Just Cause 3: I actually bought this to entertain some young nephews who were visiting. It did the trick and after they left I played through the campaign myself. It is temperamental (on PC) and the story is rubbish but it retains the whacky go anywhere do anything and blow everything up style of its predecessor.
Call of Duty: Black Ops III: Even though I have long since given up any hope of keeping up with teenagers in multi player shooters I still try to play each Call of Duty single player campaign. Black Ops III is actually one of the better ones of recent years. There are a couple of very hokey flying sequences but most of the game is solid single player action with enough sci fi themes to appeal to an old nerd like myself.
Mad Max: Is another Ubisoft style open world game. This one focusses on driving around a post apocalyptic landscape. Like most games of this sort it is an enjoyable way to pass a few gaming hours but ultimately forgettable. In terms of quality I would place this above Just Cause 3 but below Far Cry 4. The car combat is rather excellent however.
Halo 2: I loved Halo Combat evolved and I eventually got around to playing the second episode which was treated so badly on Microsoft Windows. I really would like to play more Halo. I just amn't prepared to fork out the cash for an Xbox One to be able to do so.
The Lord of the Rings: The Battle for Middle Earth 2: I loved the original Battle for Middle Earth but until recently I never got around to playing the sequel. One of the great joys of PC gaming is that it is almost always possible to find a way to get older games to work so I finally got around to trying this. It has the same wonderful Middle Earth atmosphere (the Peter Jackson version) as its predecessor but the game play has evolved somewhat with an array of new races and abilities. It feels less story driven than its predecessor but instead presents a variety of game modes and scenarios to play through.
Fallout 4: I have only recently gotten this so I haven't had much time to play it. So far it feels very like Fallout 3 which may be a good thing or a bad thing. I hope it has enough newness in it to keep me occupied.
Singularity (Again): I was in the mood for a Sci Fi shooter so I dug this one out of my library. Enjoyable if somewhat patchy.
EDIT: Secret Confession - I actually downloaded World of Warcraft and played for five minutes. My excuse is that they gave me a free upgrade to Warlords of Draenor and seven days of game time. I couldn't find any of my old characters but I created a new Orc warrior and played for five minutes and then logged out. Been there. Done that. Don't need to do it again.