1. Grand Theft Auto 5 ; The best GTA so far. I'm still amazed at what Rockstar was able to pull off with the 360/PS3 hardware. Such amazing attention to detail and a fully realized world. With its memorable character and missions and Rockstar's trademark irreverent humor, the single player was my favorite gaming experience of the year. I wasn't a huge fan of GTA Online, but it doesn't change how I felt about the game overall.
2. Bioshock Infinite ; I wish we saw more games that attempted narratives like this. While I don't think that the gameplay necessarily stands out, and the combat got old pretty fast, the world and the characters were what kept me going. It's very rare that I think about a single-player game after I complete it, but this one stuck with me for weeks.
3. Path of Exile ; (AKA Diablo 2.5) This game knows why you play ARPGs: Sweet, sweet loot! It certainly doesn't hold back in doling out massive amounts, with a myriad of interesting effects and attributes. Compared to the rather lackluster (especially at launch) loot of Diablo 3, this game actually made me care about grinding for that perfect item again. The currency system is great, and allows you to customize that uber item you found. Combine this with great co-op, an interesting ability system, a MASSIVE skill tree (seriously!) an atmospheric, "grimdark" setting and this game is definitely in my top 3.
4. Marvel Puzzle Quest Dark Reign ; When the original Puzzle Quest came out, I played it straight for probably 20 hours. I was hooked, and none of the other Puzzle Quest games since that have been able to capture that feeling for me, until this game. It's the basic puzzle quest you know and love with some Marvel characters mixed in, wrapped in a F2P shell and topped with a sprinkling of asynchronous PVP tournaments. The added depth of collecting and leveling a team of characters with powers that synergize well, is a great addition to the solid match-3 gameplay. It's also a great F2P game, in that IAP are not required at all. I have spent $2.00 in total in the game, and I'm able to be very competitive in the tournaments. I have almost 100 hours logged in this game, which is almost more than I've spent with any other game in the past year.
5. Call of Duty: Ghosts ; This year, I decided I was tired of playing by myself, and joined a clan with a group of other PC players. This made the Ghosts multiplayer one of the best COD experiences I've had, and I can't go back to playing by myself. The game itself is good, and although it doesn't stray far from the COD norms in many ways, it does deliver a refined multiplayer shooter. It felt more balanced at launch than almost any COD I've played, and does not have any crazy overpowered weapons, as many of the other iterations have had. The singleplayer is always an afterthought for me with these games, but it was a fun themepark ride, with some great setpieces. Overall, one of the better additions to the already crowded COD stable.
6. Desktop Dungeons ; As an early backer, I played this game a bunch while it was in beta. At the time, it was just a procedurally generated dungeon crawler/puzzler, with no frills. I loved it, and played a ton of it, but something was missing. Now, in the release version on Steam, there is a campaign wrapper for the great dungeon gameplay. This adds a great deal to the game, and the sense of progression is very rewarding. The game is hard, but fair, and learning the tricks that it will take to beat some of the harder maps can take a while. Definitely in my top 3 roguelikes, if it can indeed be considered one.
7. The Swapper ; This is an beautiful, atmospheric puzzle game set in an abandoned space station. It also happens to have some of the best mind-bendingly difficult puzzles this side of Braid. The feeling of isolation and claustrophobia is always with you as you slowly unravel the story through hints in the environment. I appreciate it when games don't spoon feed you the story (see Dark Souls), and it definitely adds to the aura of mystery that surrounds this game.
8. Shadowrun Returns ; I began to have doubts about backing this game on kickstarter several months before it was to be released. I wanted to withhold judgement until I played, though, so when I played it for the first time, I was hoping it would blow me away. It didn't, though, and after putting an hour or two into the game, I gave up. I didn't pick it back up until 3 or 4 months later, but I'm sorry I waited that long to give it a second chance. Once you get past the slow start, the game really picks up. I love the setting, and the turn-based combat felt wonderful. While the base game was a bit short, I'm excited to see what the Berlin campaign brings, as well as what the community comes up with for custom content.
9. The Incredible Adventures of Van Helsing ; This is a fun ARPG that doesn't take itself too seriously, but I think it can stand alongside some of the other great ARPGs in it's own right. It reminded me a lot of Titan Quest, and that's definitely a good thing. The skill system lacks some variety, but the loot is great, and the monsters are a refreshing blend of European mythical creatures, instead of those tiresome Demons. The steampunk setting is pretty unique in the genre, and fighting mechanical soldiers and electrical werewolves never gets old. For just $15 on steam, it's also easy on the wallet.
10. Call of Juarez Gunslinger ; I was very skeptical about this game when I first heard about it, as the previous gunslinger games have ranged from OK to, most recently, downright bad. I went in with fairly low expectations, but the game definitely won me over. You play a bounty hunter searching for the men that killed your brother, but the game all takes place in the context of the bounty hunter, now an old man, retelling his tale to a group of admirers in a saloon. Sometimes he forgets details, and sometimes he gets called out on some fact or other by one of the the listeners. The game world changes as he narrates and fixes his mistakes, which makes for some great moments. The combat is fairly standard, but the skill trees you have access to allow you to tailor your approach to specfic weapons or playstyles. The duels in the game are awesome, and make you feel like a badass when you outdraw your opponent. I haven't gone through the arcade mode, but it takes full advantage of the combo kill system that allows you to string kills together to go for a spot in the online leaderboards.
x. Kingdom Rush Frontiers ; I loved the first game, and this one was no exception. Easily the best mobile tower defense game I've played, it's challenging and addictive.
2012. XCOM: Enemy Unknown ; I wanted to play this when it first came out, but I ended up getting it for free with Bioshock Infinite on Steam. I had a great time playing through the game, and I found it quite challenging. It's a great feeling starting with green recruits and turning them into ubersquad with alien weaponry and power armour. And then inevitably losing your best soldier to a random alien grunt that he should have easily stomped. That's XCOM.