All of your members have to be loyal and your sjip has to be completely upgraded.
You have two walkthrough before the end game against the huge terminator.
The first part, you use for the heat vents;
Kasumi (if you have her DLC)
The Fire Team
Take any other team member with you will be fine.
The second part, The Long Walk
Before the long walk, you need someone to get the survivors back to the ship, if you didn't have any survivors, skip this part.
Use Mordin or Zaeed (if you have that DLC)
The Long Walk
The Fire Team;
Take with you on the walk either
Samara or Jack For the biotic barrier protection.
Then take any other two you please (I seriously recommend Grunt)
The end run doesn't matter, I have had all of them survive.
[Edited by tommy6860, 4/12/2011 5:00:14 AM]
Always use Mordin as the escort to guarantee he doesn't die. In the HOLD the line part of the mission take the least combat savy people with you and make sure you leave Zaeed and Garrus (don't choose them) so they can hold the line. These guys will even save non-loyal squad members. You have to realize even loyal squad members can die if you don't pick the right person especially for fireteam duty.