Halo 3 ODST is probably the best of the prequel games. Seeing as we don't have a whole lot in the category that isn't from the Zelda series, and the most notable of the past few years was DMC (Which was both good and bad), this is up there. When I say best of the prequel games, I'm not counting things like Zelda because they just continue to make prequels.
The bad. I may be wrong, but they did change the flight mechanics in this game, it even seemed that it was just for this game. Another thing that I didn't really like was the lacking soundtrack. They seemed to just reuse songs, even though the piano song did pull of the feeling of the scene that it was used in quiet well, there was maybe around 5 or 6 other songs that I could pick out. Though I beat the game in around 3 hours.
The good. The game has massive replayability if you love your achievements. It also has the fire fight game mode that can keep you entertained for hours on it's own. The game play itself is pretty solid and I had fun playing it. I didn't mind the fable-esque animations for the characters when they were talking either.
Final Verdict:
I liked the game. I would suggest getting a copy at your local gamestop or eb games, it is worth the money.