(Disclaimer: While I work in the video game industry, I'm not a professional critic. There are plenty of games I didn't get to play, so this list isn't meant to be all-inclusive. Also, these are just my personal opinions, and are not representative of my employer.)
Honorable Mentions (in alphabetical order):
Binary Domain (X360) -- Cover-based shooters are a dime a dozen these days, but this one was better than most. Very good story, well-written characters, and the squad 'trust' system was a nice addition.
Black Mesa (PC) -- This free mod was over seven years in the making, but worth the wait. No matter how many times you may have played through the original Half-Life, they tweaked just enough to make it feel fresh. Mod DB even named it 'Mod of the Year', topping the mighty Day Z.
Counter-Strike: Global Offensive (PC) -- If it ain't broke, don't fix it! A respectable update to a classic. Gun games never get old.
Diablo 3 (PC) -- Series veterans had a lot of complaints, but as a noob, I found a lot to like. Now if they'd only add PvP...
Hotline Miami (PC) -- Super Meat Boy combined with an 80's serial killer movie. Original and disturbing. With tighter controls, it could've ended up in my top 15.
Plague Inc. (iOS) -- I don't usually get into simulation games, but this one grabbed me. Infect the world!
Spec Ops: The Line (PC) -- The story dares to ask questions about the nature of war and how it affects the human psyche. A war-torn Dubai makes for an unforgettable setting, and the squad mechanic works surprisingly well.
Treasures of Montezuma Blitz (PS Vita) -- Addictive free-to-play puzzle game has caught a lot of my free time this year. It launched slowly, but patches improved it immensely. If you have a Vita, you should be playing this.
Top 15 List
15. The Darkness II (X360) -- I was a big fan of the original. It had one of the better stories you'll find in this generation. I didn't know what to think when they announced a sequel, from a different developer, and in a cel-shaded graphic style, but they did a commendable job. It looks and plays great, and the story is solid (if not quite as strong as the first game).
14. Sonic & All-Star Racing Transformed (X360) -- Even better than the past few Mario Karts. Nice variety in the gameplay for the driving, boating, and flying sections. A good amount of depth in the campaign, and full online support on all platforms. You don't have to be a Sega fan to enjoy it either!
13. Trials: Evolution (X360) -- 'More Trials' is really all they had to deliver, and that's what we got. It kept me up well past bedtime for weeks. The controls are still satisfying, and the challenge of the later levels is still heart-explodingly difficult.
12. Ghost Recon: Future Soldier (X360) -- I liked this more than the previous two Advanced Warfighters. While it doesn't have much in common with the original Ghost Recon games, the pacing is better and it's much more polished. The multiplayer doesn't reinvent the wheel, but the three squad classes have a nice variety and balance.
11. Dishonored (X360) -- An exceptional blend of Thief and Bioshock. The story was good up until the final act. One of the better debuts this year, and I'm very interested to see what they'll do in the inevitable follow-up.
10. Halo 4 (X360) -- Halo Reach was a respectable swan song for Bungie, but I think this debut from 343 Industries is the better game. The story was the best since the original, and the graphics prove that the Xbox 360 still has some tricks up its sleeve.
9. XCOM: Enemy Unknown (PC) -- I have never liked turn-based strategy games. And yet, I really like this turn-based strategy game a lot. It helps that it's squad-based, and that they don't have you micromanaging every little detail. I haven't put nearly as much time into this as I'd like, but that won't last long.
8. Call of Duty: Black Ops 2 (X360) -- The best game Treyarch has ever made, and definitely the craziest. Futuristic weapons (wrist-fired grenades, weapon sights that see through walls), a 'play-as-the-bad-guy' cut scene that turns into a machete massacre, a floating ocean city, 80's flashbacks of firing RPGs from horseback, Michael Rooker with spikey hair .... it's unapologetically insane, and the most fun I've had with a CoD game in five years.
7. Forza Horizon (X360) -- I haven't been drawn into a racing game since Test Drive Unlimited and Burnout Paradise. Both of those were huge open-world games that were more arcade than simulation. This game is more sim than either of those, but is forgiving enough. It's relaxing to just drive around and see the sights, and when you want to actually race, it's a challenge but not punishing. (*FYI: I didn't get to play Need for Speed: Most Wanted, but reviews say it's a lot like Burnout Paradise (same devs) so that one may have ended up near this slot too).
6. Mark of the Ninja (X360) -- The best pure stealth game I've played in years. Playing it felt like the developers spoke to me beforehand, because they somehow knew what I've always wanted in a game like this. The Tenchu games came close, but this is true Ninja Heaven.
5. Journey (PS3) -- Probably the best $15 you can spend this year. It contains not a single word of dialog, and yet inspires more emotion than almost every other game I've ever played. Until Fumito Ueda can finally deliver The Last Guardian, I'll be playing through this again.
4. Mass Effect 3 (X360) -- Even though the story juggled the ball a bit near the goal line, the sheer level of scope and imagination on display is undeniable. In these three games, Bioware accomplished something that we may never see again in this industry. They even added a PvE multiplayer mode, and it was a lot more fun than anyone expected.
3. The Walking Dead (PC) -- If video games ever expand into a larger art form, we may look back on this as one of the turning points. Even though it's more of an interactive novel than a traditional game, Lee and Clementine are the most 'real' characters in any game I've ever played. Struggling for their survival will have you making moral choices that you'll think twice about, and then you'll second-guess those choices after the fact. By the end of the final episode, I was an emotional wreck. This game had me excited for what this medium can eventually become.
2. Borderlands 2 (X360) -- The first Borderlands was a revelation, and scratched an FPS/RPG hybrid itch most didn't know they had. While the sequel doesn't take many risks, it delivered an even better experience than the first. The minor tweaks made to the user interface, the quest delivery, the skill trees, the NPC dialog, the hub world -- all were improvements. The levels feel bigger, and the score from the always-amazing Jesper Kyd was great too. The 'True Vault Hunter' mode and the upcoming DLC guarantee I'll be playing this well into the next year.
1. Far Cry 3 (X360) -- I punched a shark in the face.
Just when I thought I was burned out on open-world games, this one delivered more 'holy crap' moments and genuine laughs than anything else I played this year. It made me feel like the star of an action movie. The first two Far Cry games were ambitious but uneven. This one corrects all the wrongs, and has a blast doing it.
The tagline of 'Skyrim with guns' isn't too far off. While there are many ways to get around the massive island (cars, jeeps, jet skis, patrol boats, ziplines, hang gliders, wingsuits), exploring on foot while hunting was just as much fun. The "L.A. trust-funder turns into jungle mercenary" story is enjoyable (especially by normal shooter standards, even if it starts to tail off near the end), and the voice acting is stellar. The side missions are varied too, and are short enough to not overstay their welcome.
The AI is fairly random, which leads to some memorable moments. Sometimes while trying to capture a base, I spotted a caged animal inside. You can shoot the cage door lock and let the animal out, and it will distract the bad guys. At one point, I was observing a base through my camera when a black bear came out of the jungle and started attacking everyone. Instead of firing at them, I just watched as they screamed in horror and tried to kill it, and failed. The bear ripped every one of them apart, and then I got credit for capturing the base. I was in the right place at the right time. And I couldn't stop laughing.
Besides a lengthy campaign, and tons of post-game exploration and side missions, there is also a decent co-op campaign, a full competitive multiplayer, and a map editor. It's not all perfect though. The graphics on Xbox aren't as sharp as I'd like, but I suppose it's a fair trade for drawing such a huge open map. The multiplayer feels a little floaty when compared to other AAA shooters. However, I think the biggest omission is not being able to start a "New Game Plus" and carry your unlocked perks and weapons over into a new game. But, these are all minor complaints in my book. It's the most fun I had with a game this year.
Also, did I mention that I punched a shark in the face? Top that, 2013.