Written by rvbomally (but with plenty of contributions from other members), Ad Astra Per Aspera is one of the best timelines on AH.com, despite only having started back in 2011. Best described as 1984 IN SPACE!, the timeline's grimdarkness rivals that of Warhammer 40k. Three galactic dictatorships lord over four trillion souls, galactic war is the status quo, democracy is virtually extinct, and a dozen conquered alien races are used as either slaves or cannon fodder. A detailed galactic map can be found here.