Although in many ways the second game wasn't as good as the first, it set up the groundwork for the third and, in my opinion, best of the trilogy. (I call it a ‘trilogy’ because although Gyakuten Saiban 4 has been released in Japan and will be translated and released outside of Japan next year, it focuses mainly on new characters.)
What makes it so good? Again, writing and story, the two most commonly overlooked components of games. These are characters you care about, whose stories you want to see through to the end. Gameplay is almost the same as the first game, and exactly the same as the second, but the pacing of the cases is much better here, with a good balance between investigation and courtroom battles. The cases also have a much better ‘flow’, with only a few places where it seems you've done everything with nowhere further to go. However, with perseverance and a little “ask everyone about everything”, even these places can be overcome without too much frustration. The courtroom music has been changed again, better than the second game but still not quite as good as the first.
Although the first four cases range in quality between good and great, the final case is fantastic. It's fill with twists, turns, unexpected developments, revelations and relationships, surprise cameos from characters you've seen before and a conclusion that'll have you laughing, cheering and maybe even shedding a tear or two.
To get the most out of this game you should have played the first two before starting, but fortunately that's not a chore at all. A great ending to a great trilogy!