5. Borderlands 2
"Well done! Your ability to walk short distances without dying will surely be Handsome Jack's downfall" - Claptrap
Everything a great sequel should be, Borderlands 2 took the core mechanics of the first game and tweaked and perfected them, adding in fun new characters, more environmental/weapon variety and a compelling villain. Missions were more dynamic and interesting. It looked gorgeous, had a fantastic soundtrack courtesy of the always reliable Jesper Kidd, played smooth as hell and although it became a little grindy towards the end (and EXP-LOADERS can burn in hell), it was almost always a ton of crazy, hilarious, violent fun.
4. The Walking Dead
I have mixed feelings on the current epidemics of a) zombie games and b) all the "good" stories in gaming being relentlessly bleak and miserable. But I can't deny that this game affected me. The story's huge emotional punch was almost solely due to the ingenious character of Clementine and her relationship with Lee. I can overlook the rudimentary puzzles and lack of engaging, challenging gameplay elements when I genuinely care about the characters this much.
When Clem is in danger you really freak out, you get stressed, you feel the fear because the writers have made you love her. She is innocent but sturdy, sad but hopeful, scared but trustworthy and never, ever a burden. She is the goal in the game. The Walking Dead has set a new precedent for character interaction and I would love to see some more games take its example and expand upon it.
3. Mass Effect 3
Mass Effect 3 has ruined Firefly for me. I am currently watching the much-loved sci-fi series for the first time and though the characters are wonderful, I am terrified to engage with them and emotionally invest. I am afraid that if I give that much of myself to a story again and trust the writer with my emotions, then I will once again have my nerdy little heart shattered. So I watch while doing my best not to care too much about Mal and his merry crew and it feels like I'm betraying them and their story.
This is the best way I can sum up the effect Mass Effect 3 had on me. Never has a story made me feel that way, let alone one in a videogame. People not invested in the series don't really get where all the "entitled whining" comes from but take it from me - it was a real sucker punch and something I'll never, ever forget as long as I live. For that reason alone it deserves a spot here, but there's so much more.
Mass Effect 2 was my Game of the Year in 2010. The weird part is, ME3 did a lot of the things ME2 did, but better. Maybe it should be my GOTY ... but there are so many things that conflict the emotions.
There's the Tuchanka mission - probably one of the best written, perfectly presented 2-3 hours in gaming history, with 3 games worth of buildup all coming to a head for the Krogan in a glorious, hugely rewarding, emotional climax.
Then there's Javik. Don't let anyone ever tell you Javik is an "optional" character. This is a lie. The infamous DLC Prothean is essential not only to the story lore but also to Liara's character arc. You learn more about Mass Effect history in Javik's DLC than in the entire rest of the game. EA making him a paid-for add on to exploit fans' love of the lore was a dick move, end of story.
There's the climax of the Quarian/Geth conflict. Seeing your old buddy (or lover) Tali play such a pivotal, emotional role in her species' fate was hugely rewarding, as was Legion's story.
Then there was the God awful mission menu that didn't bother to tell you your progress as you wasted hours of your life on another coma-inducing planet scanning minigame then more hours running up and down the citadel to maybe bump into people who might need that freaking artifact you found on some random moon somewhere.
There's the wonderful character interactions, the many magic, tragic moments between Shepard and his crew that bring tears to your eyes and make you do fist pumps and want to kick those reapers' big purpley-black shiny metallic asses back into dark space. There's the combat which is an elegant, refined mix of the previous 2 games. The growing sense of a galaxy coming to terms with its imminent doom and the knowledge you're the only one who can put it all right ...