I'm bad at top fives because I can't remember what exactly has been released and I'd rather just spew text than filter out the Search here and THEN make my post ;)
Halcyon 6
... is certainly my favorite release this year. Excellent game, all I had hoped / wanted for when I grabbed it a few weeks back. Ton of fun gameplay with a great set of core mechanics. I love slowly building my fleets, recruiting new officers and outfitting my vessels as I see fit.
AND they just put out a patch that strung my base up with Christmas lights and a tree - how great is that? ;)
I hope for the sequel (fingers crossed ;) ) we get more quests and random events that send us out and about exploring, full equipment options for both officers and ships and a more "Mass Effect" like system of exploration. Not necessarily exploring worlds on the ground, but more and varied ground combats / quests associated with visiting planets (and maybe stations and derelict craft?). Anyway, love the game.
Runners up:
Darkest Dungeon. The game oozes atmsophere, the gameplay loop is extremely solid and it does an amazing job of forcing the player to experiment with a metric TON of party compositions. Some get stomped, some surprise the hell out of you with how much better they are than you ever expected. And the guy had me narrating the mundane events of my life in a Lovecraftian tone for a week, so there's that. Descent into madness indeed...
Titan Quest. I've waited a long time to play this one. I actually didn't put as much time into it as I thought I would, but it was sweet to finally try out that class creation system. I'm going to dive back into this one soon and give it a proper full play.
I'm sure a few more would / will make this list but I have yet to play / pick them up. Soon! (TM ;) )