1. HD Mass Effect 1/2. And I don't mean only HD textures. Lighting,shading,animations need improvement too. All in all,around the same level like in ME3,and possibly even better.
2. All DLC included. No excuses,all DLC (including armors,weapons and alternate appereances) should be included regardless of the platform. Its a must if they plan to re-release the trilogy.
3. Integrate the DLC into the story,at a point in which they fit in best. I don't want Lair of the Shadow Broker or Arrival open up 5 hours into ME2,or Leviathan open up as soon as I finish Palaven. Make the dlc a part of story progression,so for example I can't start Thessia if I haven't completed Leviathan,and make additional cutscenes to reflect that.
4. Include ME3's combat system in ME1/ME2 if possible,and even make a few tweaks the dev team might consider necessary.
5. Seamless transition between all three games.
6. Oculus Rift support. I don't care if ME games are in third-person,Oculus Rift support for all three ME games would be amazing. Especially during space battles and big cutscenes (imagine seeing Kalros take down that Destroyer on Tuchanka with Oculus Rift,or the opening cinematic for the Suicide Mission.)
7. Kinect support for all three games. It was awesome in ME3 (yes,even the dialogue).
8. Remake Priority:Earth. Yeah,mentioning the ending is inevitable when talking about a remastered ME trilogy for PS4/Xbox One/PC.
Keep the Catalyst if you wish,but for the love of God,overhaul Priority:Earth. Scrap the entire mission,starting with the opening cinematic,and simply remake everything from scratch.
- A proper story (and less cliche writing).
- Big consequences depending on your EMS and choices throughout the trilogy (obviously not all choices you made,but some big ones like the Rachni,Quarians/Geth,the Krogan race,etc. are a must)
- Epic and well-written moments (see the Tuchanka story arc).
- A lot more missions (again,like the Tuchanka or Rannoch arc) before the actual assault on London.
- More cutscenes with variations depending on our EMS/choices.
- A much longer and higher quality "Fleets arrive" cinematic,again,with variations depending on our EMS/choices and actual ships from different races in the galaxy,not just copy-pasted Alliance cruisers.
- A brand new soundtrack composed just for Priority:Earth. The exact same soundtrack repeating over,and over again during this mission in ME3 was really annoying.
- A final showdown with Harbringer (just a personal wish,but I bet a lot of fans would love to see it).
- Overall,the kind of mission ME3 was setting up to,and the kind of mission we were all expecting.
Its a big request,and would probably take a lot of money/resources and time,but the pay-off would be huge.