Mass Effect

• Save often, the game's a tiny bit buggy.

• The classes aren't quite balanced. Full-fight or any of the fight-hybrids are the easiest, full biotic is arguably the most powerful. Biotic/tech is the hardest by a fair margin.

• Go either all Paragon or all Renegade. Like most Bioware games, ME1 punishes you for sitting the fence.

• When you're on an uncharted planet, there are always more things to be found than your map lets on. Explore areas of the map that are far away from the marked locations--you'll find hidden stuff. This is critical for completing a few annoying item collection side-quests (and you still might want to just look them up).

• The "Rich" achievement requires 1 million credits in your account, and unlocks Spectre weapons. Other gear isn't really worth buying. Regularly sweep your inventory to make a reserve of omnigel, then sell anything that's not bolted down.

• Make sure you've always got Electronics and Decryption (on yourself or a party member), but otherwise bring who you want. Characters have different inter-party banter based on who they're with, if that affects your decision.

• Talk to all your squadmates after every single mission. Especially after every big mission. Especially if you think they're cool characters and you want to unlock more character development. Especially if you want to romance them, and they're either human or blue.

• Do Noveria last, the boss at the end is significantly harder than the other two.

• It's best to hold off on any side-quests (includes the ones on the Citadel) until after you have the members you want, but before Virmire.

• There is a New Game +, which you might not use if you're playing through the trilogy, but you can use NG+ to max out both sides of the morality wheel to see all the "best" dialog in the game, without resorting to fancy tricks.

• All achievements like "use skill X 75 times" or "kill 150 enemies with X weapon" have to be done by Shepard.