Proper Co-op Missions
The multiplayer was plenty of fun, but we still think that Bioware has missed a trick. We'd love to see DLC offer a brand new mini co-op campaign. We appreciate that Mass Effect's narrative style might make this tricky, but we still reckon it's a challenge that Bioware could manage. Take Commander Shepard out of the equation, and suddenly you've got plenty of options. Perhaps the squad could make all of their choices by voting, or even act as specialists for different situations: If the decision you're making relies on tweaking electronics, the group's Engineer would get the final say.
It wouldn't be fair to expect epic branching storylines, but contained missions with a variety of outcomes could be fun to play through multiple times. Creating contained missions like this would also open up a huge range of new options: Why stick to one story, when you can hop around?
Let us fight for the Turians in the Contact Wars, or get to see Krogan tactics first hand. The Salarian Special Tasks Group would be another great target, letting us team up with friends to carry out high-security undercover missions. The manpower required to create DLC like this might make it seem totally out of the question, but we reckon it would double up as great market research: Give consumers a flavour of what's on offer, and you might just discover a full spin-off worth making.