Root Double ~ Before Crime * After Days:
This is definitely one of the best visual novels released in English in recent years. It's a great, and at times very tense, game about a group of people trapped in a nuclear facility that has a reactor melting down, and they have very little time in which to escape. Throw in some psychic powers (handled in a pretty interesting way), some conspiracies, terrorists, a murder mystery, and plenty more and you have a really interesting game. Folks who loved 999 should be right at home, as it's a similar type of game, but with much stronger character development and with "twists" that hold up better and have proper foreshadowing and payoff.
If you found yourself let down by Zero Time Dilemma, you owe it yourself to wash that out with a truly great sci-fi story.
It's on Steam. If you have any interest in this sort of story, definitely give it a go. You won't be disappointed.
The Legend of Heroes: Trails of Cold Steel II:
Okay, this is a tough one to sell in December as the 100 hour direct sequel to another 100 hour RPG, but if you get a chance, you absolutely need to play Cold Steel II. It's a really excellent RPG that improves upon everything from the first Cold Steel, and is my favorite of the localized Trails games so far. The two game long arcs pay off really well, and the game's NPC dialogue remains in top form as in all previous titles. Some of the side quests and just general wrap up from dialogue in the Epilogue just left me feeling so melancholic about the game coming to an end. It says a lot about the game when I can still tell you about my favorite townspeople and sidequests months after completing it. The main story gets pretty exciting, too, particularly the Intermission and the Finale. And the decision to make the game more open than previous games works out really nicely.
If I was to have one major complaint, it's simply that the difficulty is too low. Even on Hard I felt like I had very little challenge throughout most of the game, aside from a handful of boss fights. But this game, and the whole Trails series in general, is definitely not something you want to miss out on.
Available on PS3 and Vita.