The machine gun (forget the exact name) is my favorite weapon for the zero-grav sections, as it is accurate at long range and those sections tend to be largeish.Plus it's always easy/cheap to get ammo for.

The Plasma Cutter may be your first weapon, but it remains good for the entire game.

You find schematics and loads of goodies behind them.

Always keep one node on you at all times, to open the doors.The circular saw is also great to incapacitate quickly most of the enemies, just be sure to finish them off or else you'll get crowds of legless monsters after you in the latest parts of the game. Seriously, that thing is absolutely awesome. Nodes put into the plasma cutter are never wasted.Even the flamethrower is a little better this time around. For close range, consider the force gun or line gun. The javelin gun can work well as a long range one. You want a long-range gun and a close range crowd control weapon, as well as your plasma cutter and a 'special event' weapon, probably either the mine launcher or contact beam.

Dead space 2 inventory pc