I've had some time to think about this answer and I feel like I could probably give a slightly better response than previously.
Favorite game: Final Fantasy VII (original)
I love the story, the characters, and the combat of this game. It shows its age in a variety of ways, but I feel like the heart of the overall project still shines through, even if the passage of time has been perhaps more harsh to this game than any other in the series. But one thing I can not defend, and probably couldn't even in 1997, are the mini-games. The motorcycle chases, the snowboarding, the Chocobo racing. Nearly anything that doesn't involve traversing the overworld and engaging in turn-based battles are at best awkward and at worst completely broken. Anytime I find myself thrust into a new control setup in this game (especially in later ports), my entire body immediately tightens and I pray that it ends soon. I appreciate the ambition, but the game is far better without them.
Least favorite game: Apollo Justice: Ace Attorney
As with my last post, it's a little hard for me to think of a game that I outright despise enough to consider my least favorite game. There are certainly games I don't like that much, but it's hard to decide which games I dislike more amidst the sea of games I also hate. If I had to pick one, I think the fourth entry in the Ace Attorney series, Apollo Justice, comes the closest. Nonsensical plot, logically questionable puzzles, and.. well, that's mainly it. It's not only my least favorite in a series that I otherwise hold in high regard, it's a thoroughly miserable experience from beginning to end.
But I love the music of the game. It has some of the best tracks in the entire series. In addition, it introduces the character of Trucy Wright, who--while not terribly significant in the overall series--is one of my favorites. She's extremely cute, and while I think they could stand to do more with her, the backstory she's given is interesting enough as a basis. Please give Trucy her own game, Capcom.