Gears of War is very popular, if you like that genre you should get it, and Bioshock. I don't know how good Dead or Alive 4 is. Go to
metacritic.com/games and gamerankings.com and type in the names of the games for critical/user reviews.
Blue Dragon is a traditional japanese console rpg, kinda like Dragon quest or Final fantasy. The leader for years of FF, Hironobu Sakaguchi, left Square Enix a few years back to form a new company, Mistwalker. He took Nobuo Uematsu, the FF composer, with him. Mistwalker makes rpg's on Xbox 360(although one is coming to DS) and is published by Microsoft.
Blue Dragon is their first game, and the third main guy working on it is Akira Toriyama, who did character design for Dragon ball z, Chrono trigger, and Dragon Quest. This game is very popular in Japan.
The reviews are good for this game but there are a few signifigant flaws. One is that people don't like the character design as much and also that they think the game is poorly paced sometimes, plus there was a third main flaw I can't remember.
Check out my thread "My thoughts on Blue Dragon" which explains my short review. I don't really like any aspect of the game too much: story, characters, battle system, graphics, sound, controls. Also, the game is for a younger audience than my preference. Mistwalker's next game Lost Odyssey, should appeal to a closer audience to Final Fantasy.