1) allow us to play the ME3 intro and Mars mission with a different casual outfit and a custom armor
2) fix the ME3 journal
3) allow us to immediately pass through the scanner after exiting the war room in ME3. It's very annoying to wait like that after every mission
4) Veteran difficulty in ME3, where Shepard deals Hardcore damage against enemies but receives Normal damage
5) more face customization options in all three games -- at least add more hairstyles, beards and bring back the ME1 scars
6) all DLCs should be available, including the pre-order bonuses and the Collector's Edition DLCs (except for the mech dog)
7) all multiplayer weapons and armors should be in singleplayer. Why no Phoenix armor for Shepard? Maybe make all multiplayer powers available as bonus powers for Shepard.
8) more unique outfits and armor customizations in ME2 and ME3. Also, don't just provide the armors in one piece, split every available armor into parts so we can customize however we want. And make it possible to customize the colour of the visor.
9) Remove Shepard always carrying the M-8 Avenger during cutscenes. Or at least make Shepard carry the M-7 Lancer instead.
10) allow us to listen to any ME soundtrack in Shepard's cabin
11) batarian gauntlet heavy melee attack for Shepard
12) it's not possible to reset Javik's powers. Fix this.
13) allow powers to stay active during cutscenes in ME3, just like in ME1 and ME2
14) extra armor outfits for all squadmates in ME2 and ME3. Why doesn't everyone have a helmet and full body armor? This always annoys me. Javik doesn't have a helmet, his knees and fingers are exposed. Please change this. Samara is one of my favorite characters, but I hardly used her because of the high heels and exposed body. Just give her the Justicar armor from multiplayer and I'll be very satisfied.
15) in ME1, when looking at Earth from the surface of the moon, the image of North America is reversed. Fix this.
16) the Armory room from ME2 should be available in ME3
17) enemy bodies should remain instead of disappearing
18) minerals do not import properly as war assets. Fix this.
19) default female Shepard from ME3 should be available in ME1 and ME2
20) give us Oleg Petrovsky's casual outfit, but replace the Cerberus logo with the Alliance logo. Also, why not allow us to wear Cerberus casual outfits if we so desire?
21) allow us to import ME2 squadmate outfits into ME3. If squadmates were wearing the alternate outfit in the imported save, then they should wear that same alternate outfit throughout ME3.
The things I really wish would happen in ME3, but probably won't:
- An ending slide showing a Prothean colony, similar to the one on Ilos, with stasis pods that are still functioning. Implying that many Protheans are still alive and trapped in stasis.
- better walking and running animations.
- Miranda being recruitable after Horizon, and we can choose her instead of EDI for the Cronos mission.