/r/Iama - 8,521,238 subscribers
/r/science - 8,595,726 subscribers
/r/movies - 7,662,117 subscribers
/r/circlejerk - 254,505 subscribers
/r/gaming - 8,022,320 subscribers
/r/history - 3,431,562 subscribers
/r/art - 3,256,241 subscribers
/r/crappydesign - 189,355 subscribers
/r/askreddit - 8,917,673 subscribers
/r/sexwithbears (sex with hairy men, not real bears) - 233,144 subscribers
/r/law - 40,776 subscribers
/r/listentothis (submissions restricted) - 3,354,651 subscribers
/r/PaoMustResign/ (has been down a while as a protest) - 7,535 subscribers
/r/spain - 5,829 subscribers
/r/splitdepthgifs - 41,023 subscribers
/r/PiratesoftheCaribbean - 323 subscribers
/r/ienjoybathing - 124,835 subscribers
/r/hittableFaces - 24,345 subscribers
/r/IveFappedToThis - 30,760 subscribers
/r/Debate_Anarchy - 64,289 subscribers
/r/videos - 8,082,138 subcribers
/r/Unexpected_Anarchy - N/A
/r/ricearoni - 364,435 subscribers
/r/buyitforlife - 170,159 subscribers
/r/gadgets - 3,427,275 subscribers
/r/starcitizen - 51,971 subscribers
/r/ImGoingToHellForThis - 459,391 subscribers
/r/XtraSidePrkBnsAtFdTrk - 119,439 subscribers
/r/de_iama - 66,824 subscribers
/r/SubredditCancer - 7,979 subscribers
/r/EatCheapAndHealthy - 246,228 subscribers
/r/SAVEBRENDAN - 415 subscribers
/r/NoTap - 2,260 subscribers
/r/badphilosophy - 10,955 subscribers
/r/collegefoodporn - 2 subscribers
/r/GlobalOffensiveTrade (read only) - 36,962 subscribers
/r/technology (read only) - 5,146,693 subscribers
/r/DonaldTrump - 11 subscribers
/r/KarmaWhoring - 18 subscribers
/r/4chan - 655,245 subscribers
/r/falloutlore - 11,572 subscribers
/r/timanderic (handed to /pol/) - 20,852 subscribers
/r/gaming4gamers - 29,239 subscribers
/r/torrents - 50,413 subscribers
/r/bombay - 16 subscribers
/r/GTAindia - 2 subscribers
/r/sexypizza - 5 subscribers
/r/pohatuinaction - 1 subscriber
/r/oldschoolballs - 166 subscribers
/r/books - 5,103,352 subscribers
/r/BlackPeopleTwitter - 401,375 subscribers
/r/netsec - 134,403 subscribers
/r/soundcloud - 1,032 subscribers
/r/lewronggeneration - 52,233 subscribers
/r/portugalCaralho - 1,596 subscribers
/r/dailydouble - 12,215 subscribers
/r/seo - 24,671 subscribers
/r/OnOff - 168,990 subscribers
/r/fallout - 221,890 subscribers
/r/eder - 155 subscribers
/r/squaredcirclejerk - 1,405 subscribers
/r/theonion - 10,749 subscribers
/r/anonymous - 28,766 subscribers
/r/LifeProTips - 4,112,364 subscribers
/r/thepopcornstand - 7,087 subscribers
/r/jobfair - 18,920 subscribers
/r/gravityfalls - 22,501 subscribers
/r/TheAntlers - 218 subscribers
/r/wtf (read only) - 4,596,825 subscribers
/r/hiphopheads - 294,066 subscribers
/r/downtonabbey - 11,252 subscribers
/r/music - 7,391,288 subscribers
/r/lazyass_tiger - N/A
/r/htgawm - 3,310 subscribers
/r/srssucks - 12,505 subscribers
/r/greysanatomy - 7,243 subscribers
/r/InsightfulQuestions - 38,413 subscribers
/r/trackers - 47,245 subscribers
/r/WouldYouFuckMyWife - 29,169 subscribers
/r/bookclub - 19,529 subscribers
/r/atheism (read only) - 2,090,096 subscribers
/r/MassiveCock - 31,461 subscribers
/r/MeanJokes - 42,830 subscribers
/r/ProtectAndServe - 28,002 subscribers
/r/askcarsales - 9,732 subscribers
/r/candidfashionpolice - 54,309 subscribers
/r/nosleep - 3,274,466 subscribers
/r/Pokemon - 446,648 subscribers
/r/documentaries - 3,377,766 subscribers
/r/MorbidReality - 187,712 subscribers
/r/todayilearned - 8,782,268 subscribers
/r/fiftyfifty - 265,464 subscribers
/r/fo4 - 16,897 subscribers
/r/blackpeoplegifs - 87,663 subscribers
are down too. This is not a complete list.