Alright so since you're a home decorator expert what kind of wallpaper or paint should I go with next since this is now the home improvement megathread.
Silk paint if you have grubby walls, since you can wipe it down without damaging the paint.
However it may show up imperfections in the wall unless you replaster and smooth.
Or you could use matte instead, if you keep your filthy hands off the wall, as it can't usually be cleaned so well, but looks nicer.
I wouldn't bother wallpapering. I don't think you'd do it right and it's not worth doing if you aren't capable of doing it properly or can't afford a nice wallpaper.
And anything too nice will clash with your awful curtains and carpet/rug.