For me, Titanfall. I feel like every other post I've made to this forum this year has been about Titanfall. To repeat what I've said countless times, it's one of the most balanced multiplayer games I've ever played. I've put around 370 hours into it so far and I still play it daily (although not as much). The free updates to the game that have added new game modes and improved the balance have also kept the game fresh for me. I feel like a lot of people only scratched the surface of it because there were few unlocks and it feels a lot like Call Of Duty in the beginning. The games depth isn't in tonnes of unlocks but in the improvement on the vast majority of things you can do with movement both as a pilot and a Titan. The game is all about efficiency. As a pilot, it is about movement efficiency. Sprinting everywhere is not an efficient way to get around. The game encourages you to wallrun and wall hop by making them faster actions than sprinting. As you get better at learning routes around the map that reduced the amount you sprint, you can start to run flags in under 30 seconds easily. It's an interesting system where the reward for learning it is better than any weapon unlock would be. As for the Titans, I would compare the Titan Combat to Dota. It's lane based (not explicitly) and much like Dota, winning lanes is a priority. Lane victories allow Titans to gank (like Dota). It's rarely about the Titan with the larger amount of health wearing down the other. As a Titan, you are given several options in a fight and careful management of those resources can turn a 2 vs 1 situation into a victory.
I enjoyed Sonic up to Riders but up to that point, I had purchased few games that were not Sonic games. I got a late start on gaming so I didn't know what games to get so I went with the game I enjoyed the most in the bundle I got. When I bought an Xbox 360 and a Wii, I realized that everything I had played was only good due to it being my only experience. I started at Sonic Adventure on the Gamecube and I liked Adventure 2, Heroes, Shadow and Riders.
I enjoyed Enslaved for what it was even though it was a little simple and DmC is probably my second favourite Character action game after Bayonetta. I prefer DmC to the older Devil May Cry series just due to the story. Ninja Theory made a character that seemed like a douchebag (much like DMC3 Dante) from the promotional material into a great character. Ninja Theory's games are good at telling stories with very few characters which allows them to focus on them more compared to a game of a similar length with more characters.
I've only played the Borderlands games and some of Duke Nukem but the stories in those are not entertaining whatsoever. Specifically with Borderlands 2, it feels like they are trying too hard to be funny and I barely give a shit about any of the characters.