The Mass Effect Trilogy has been one of the most awesome stories I have gotten to play through and it's not over yet. With Omega hitting at the end of the month and Citadel DLC on the way, it seems things are going to get bigger in Mass Effect 3. However, there are things that I think would be really awesome. I'll list some here.
-The first thing that comes to my mind is this. "Harbinger and the Collectors." As we know, the Collectors have returned in Multiplayer apparently from dark space. This illustrates that the Reapers did take some Collectors with them so that they would have a ground force when they first invaded in our cycle. That being said, A Harbinger encounter and Collectors would be a fresh area to explore in Mass Effect 3. A possible Harbinger confrontation that results in Harbinger's retreat and a "We'll meet again." sounds fitting in my opinion.
-Second, mixing in vehicle based sections would not hurt either in some of these missions. I think it would be a fun way to break up the combat in new and innovative ways. Working in Geth enemies that are currently exclusive to the MP and perhaps integrating new ones would be even cooler if you could come up with an in-universe explanation for it.
-Third, bringing in sub plots from the novels, comic books, and handheld games might be a good idea as well. Would be fun to to do missions related to those media. Also good incentives to bring in new Cerberus and Reaper husk units when it comes to the combat aspects of the DLC.
-Fourth, while I'm not dying/begging on my hands and knees for this one, having a DLC that ties up the dark energy plot in a new way would be interesting to do. Make it so that this plot becomes relevant to the war and figuring out why dark energy causes star expansion may help discover ways to harness control of dark energy and use it more to our advantage and so on. Mixing in some old friendly faces like Shiala and Gianna Parasini never hurt anyone.
-Fifth, again while not dying for it, this would be cool. Cerberus plots related to the rachni, the thorian, overlord, the mass effect:infiltrator projects and all their other operations and really getting a feel for the smaller parts of their overarching operation. Not necessary, but would be cool.
-Finally, while this one is a MAJOR shot in the dark (hence why I will never expect it but would like it) is a Miracle of Palaven DLC. Witnessing the events first hand, preventing Kal'Reegar's death, and getting Garrus's sister and father safely off Palaven. Would be awesome me thinks.
-First, we have a turian female model. We need turian female kits. Mixing and matching races with classes like they've been doing as of late is also welcomed. Would also not mind more ExCerberus characters as well as Merc, Shadow Broker Agent and Spectre classes.
-Second, would like powers that remain unused to be used up in addition to any new stuff. Still wonder how Defense Matrix, Defense Drone, Dominate, Slam, Flashbang grenade etc..go unused
-Third, guns, mods, and gear are always welcomed. Personally, I'll take a salarian sniper rifle to go.
-Fourth, NEW ENEMIES. Any new ones brought into the SP could transfer over to MP. If it's a significant amount, just restructure them into standalone factions.
-Fifth, I would a boss objective...two bosses per faction. 1 for indoor maps. 1 for outdoor. Example:Harvester for outdoor maps on reaper faction. Rachni Brood Warrior husk for indoor maps on reaper faction.
-Sixth, I like maps. More would be great. Mainly, I would like homeworlds, Omega, Illium, and maybe some other planets visited by Shepard in the trilogy. Hazard Maps are a neat addition and something like a Reaper Capital Ship hazard on FB Vancouver is awesome in my opinion.
-Seventh,more appearance customization. Meaning the following: More color choice for armor and more diverse skin tones. More choice for patterns. If possible, maybe alternate appearances?
-Eighth, more diverse challenges with unique banners and titles. Never hurts to have more to show off.
-Finally, shot in the dark here but new modes would be cool.