Which game should I buy Mass effect 2, Metro 2033, or Bioshock 2?

I have played Mass Effect 2, and it’s an awesome game, but from the looks of it you are more of a fan of shooters. The Mass Effect games are RPGs (Role Playing Games), not shooters.

Can’t say anything about the other two, haven’t played them.

Well, you might want to play through Bioshock (the first one) before you play the second, because it will help you get a better understanding of the story, which is truly an amazing story line that needs to be enjoyed thoroughly.

I haven’t seen all of Metro 2033, but so far it look amazing and it has a story that keeps you locked into the game.

Of course, my review of these two games come from the Xbox360 perspective.

All three are excellent options, but like Bam said Mass Effect 2 is more of a hybrid RPG/Shooter. Bioshock 2 is an excellent game, but feels like more of the same if you’ve played BioShock 1. Metro 2033 is a game I have some issues with but still enjoyed. It’s brutally difficult for one, and brutally inefficient as well.
The difficulty curve is massive, pitting you against creatures in the dark for one moment, then fully armed neo-nazis the next. As for being inefficient, it’s a system hog. STALKER, Clear Sky, and Call of Pripyat all suffer from similar issues to Metro since they all use the same tech. They run choppy and sluggish on all but the most powerful machines, especially if you want to use DX11.
I’d say go for Mass Effect 2, it will entertain you for a very long time, provides a lot of re-playability (which BS 2 and Metro 2033 do not) and is just plain fun.

I was largely disappointed with Bioshock 2 – but I certainly wouldn’t buy it for the fact that it can be beaten in a day or two. If you played 1, it will feel very mundane – though the story lives up to it’s originality expectations (heavily politically/sociologically influenced; Ayn Rand’s objectivism). Which for that matter, the story would make a better short film than it did a video game.

Metro 2033 – Didn’t play it, looks cool.

Mass Effect 2 – Didn’t play it, either. Seems the most rewarding out of all of your choices but it really boils down to your style.

You didn’t say what kinds of games you like. The first Mass Effect was an RPG with elements of a shooter, the second Mass Effect was a shooter with elements of an RPG. I like RPGs and so I would recommend either Oblivion, Morrowind, or Mass Effect 1. Oblivion or Morrowind if you like swords and sorcery. Mass Effect if you like futuristic technology.

I’d definiteley go for Mass Effect 2, its an outstanding game, Bioshock 2 would be my 2nd choice for you.