Easiest place (For me anyway): Medium laboratory, left side. Jump up to let the enemies in, take them out with some sort of shotgun or rifle, let your health regenerate, and repeat. Favorite weapons: PANCOR and M-1187.
Wait a second! This is supposed to autosave after each battle. If that's true, how come every time I get back on, I have to start over?!?! Is this happenning to anyone else? DX<
Nevermind! In sucky Bowser's room, jump into his chamber, then keep jumping. Once you can see your feet on the ceiling, go as far as you can to the left. Viola! You are now in the White Room!!!