Still Mass Effect 2. Holy crap this game just keeps getting better and better. At around the half way point any single section from the game - even the free DLC levels are epic enough to be the last level in any other action game, it is just that awesome.
I beat The Lair of the Shadow Broker DLC Orta bugged me to get when it was on sale, and I could not thank him enough for making me do so. That might have been the best DLC to any game I can think of and it lasted hours upon hours. Solving the attempted murder, the chase scene, storming the base, everything else that came after... Just absolutely brilliant.
I kind of entirely dropped Phantasy Star IV to get through this game, and I am worried that just as soon as I am done with the game I will want to play through it again with an entirely new set of characteristics and all that. I will be sure to definitely beat PSIV though, I have to!
I haven't played any Mass Effect games yet (planning on picking up ME2 on PS3), or Halo Reach, so I can't really argue anything. I'm really looking forward to Uncharted 3 and Valkyria Chronicles 3 though.
I think you will love the game, but I think it really sucks for PlayStation 3 players just now getting into the series, because much of the history of the characters and worlds (although explained in good enough detail in the game through conversations and the journal) may be lost with them.
It is the same thing as Shenmue basically, it sucks that some people started off with Shenmue II and could not experience the greatness of the first outside of the DVD movie included in the Xbox release.
There is a bigger issue with this though, characters you saved or spared might change the story. For instance, someone I argued with in the first game who tried to kill me changed his outlook on life and became a better person for it. In this game he returned as the leader of a small group of fighters that would prosper greatly, if he attacked me in the first game, he would have died and obviously not appeared in the second game, entirely changing the state of potentially an entire civilization. Where as in Shenmue you would of just not had that cool Ristar figure anymore.
I wanted to like Mass Effect but the pacing was too slow for me, it seemed like I spent all my time in lifts or talking to aliens.
I enjoyed Mass Effect 1, but it was kind of a mess. The characters actually make fun of your complaints from the first game. Mass Effect 2 is one of the best games I played since the Dreamcast days, and I was never really a fan of BioWare outside of MDK2. I would recommend anyone who likes action and does not mind too much talking (you can skip most of it, but there is still a hefty amount of it) to at least check it out.
There is a demo available, but I was not crazy about it personally, but I cannot really put my finger on the reason why. Still, it could not hurt to try it out.