I'd love to see some DLC about the Fallout: Tactics universe, It'd be awesome to see what happened to the Midwestern BOS.

I think it'd be awesome if we get to see Marcus again, and to see what happened to the Master's army.

An essential feature / mod that they should implement into the game would be a custom player radio, that just allows you to drag and drop your music into a playlist, and then it automatically plays them..

It'd be awesome if they would give us multiple choices on the UI sound of the pipboy in the vanilla game, and or pipboy customization options. (Different colored screen, text, button colors, etc.)

I really liked the Fallout 3 Mothership Zeta when another spaceship engaged a battle. That was badass. So I'd like a DLC with big battles in space. Also, they could make a DLC where you have the possibility to join the original BoS. There, you could fight huge battles against super mutants!
PS: I like super mutants, I'm not racist But I also like fighting them

Hopefully we get a DLC that involves Canada. Canada was annexed by the United States in the Fallout universe so the culture shouldn't be too different. This means that it can stick to the "pre-war America" theme that Fallout is known for. Niagara Falls would be cool to explore. It would be similar to New Vegas in a way, with all the casinos. Unfortunately it's a bit too far from Boston for Bethesda to easily explain how the Sole Survivor would get there in the first place.

Well How about some more Pre War after intro ? And maybe one of USA islands ?

I'd like a Super Mutant-centric DLC that really shows the darker aspects of their creation/presence. Like with them kidnapping NPCs and such, and you trying to save them.

I'd like to see one were you visit the capitol wasteland, if my geography is right and memory serves there was an android called harkness in rivet city so its feasable to think you could travel back there and get a look at it in a better engine

Whatever they do they better do one were you can see the aftermath of the choices you make like broken steel and not leaving you hanging like fallout nv

Something that could take us to toronto so we know what the world outside of america looks like

A DLC worldspace where a small city and nearby military base are heavily overgrown by jungle flora. Maybe the geckos evolved into velociraptors.

Honestly something like point lookout cause that DLC was super cool or something in Maine would be cool or maybe even something in Texas or a mountainous area all would be fun

I'm thinking something like The Pitt but in a larger worldspace so you could explore a more open city landscape than the capitol wasteland

I would like to see something similar to the Sierra Madre DLC from Fallout New Vegas. I loved the new enemies and just the overall story of the Sierra Madre.

I'd like to see cheyenne mountain or remnants of norad.  Or perhaps a revisit to san francisco from fo2 and then a dungeon crawl through alcatraz which could be a fallen brotherhood base or somthing

Maybe a DLC where you try to find the Liberty Bell in the Philadelphia ruins.

I think a dlc that lets you run around the capital wasteland again assuming the game will take place a number of years after F3 so you can see all that things that have changed and all the things that have stayed the same

I would like see a dlc where the Brotherhood of Steel fly to Europe to fight against the Chinese remments with Great Britain, France, Germany, Japan and Russia, that would cool to see

I'd like to see some DLC to go to Connecticut. I live right on the border of Mass and I'm not too far from Boston. If they had DLC that went near my area I would learn how to create a mod and make an exact copy of my house.