Menu -> Friends -> Search -> ID -> Enter ID -> Click portrait -> Scroll down to Guild -> Details
game.granbluefantasy.jp can be replaced with gbf.game.mbga.jp for mobile browser version.

Guild War wins/losses are taken from /gbfg/, and contribution is taken from http://gwresult.imgur.com. I do not guarantee its accuracy. Use at your own risk.
Letter in brackets is the tier they qualified into. Contributing members is next to Wins/Losses. Number outside parentheses made it into top 80k, number inside made it into top 20k.
Due to the new private guild feature added in May, some guilds cannot have contributing members added. These will have (PRIVATE) instead of the numbers described above.

Updated as of June 18th, 2017
-Removed non /gbfg/ crews. Guilds known to have recruited from IRC,Reddit,Facebook, NEOGAF, Sora's Salty Club and xieicord all removed.
-Removed /a/ crews.
-Removed crews using the pastebin to shitpost.

Guild name: FOXHOUND
Link: http://game.granbluefantasy.jp/#guild/detail/590319
Profile ID referrer: 10398742
Notable recruitment policies: Unknown
Last Guild War: Jan 0W-5L : 9(0) | Mar [A] 2W-3L : 11(1) | Apr [A] 4W-1L : 13(1) | May [A] 3W-2L : 14(0)

Guild name: Dem Bois
Link: http://game.granbluefantasy.jp/#guild/detail/705648
Profile ID referrer: 13032389
Notable recruitment policies: None
Last Guild War: Jan 1W-4L : 9(0) | Mar [B] 3W-2L : 9(2) | Apr [A] 0W-5L : 4(1) | May [A] 3W-2L : 12(0)

Guild name: Granseﾒual
Link: http://game.granbluefantasy.jp/#guild/detail/845439
Profile ID referrer: 13675529
Notable recruitment policies: None
Last Guild War: Jan N/A | Mar [B] 3W-2L : 4(0) | Apr [B] 2W-3L : 1(0) | May [B] 1W-4L : 3(0)

Guild name: TOOT
Link: http://game.granbluefantasy.jp/#guild/detail/844716
Profile ID referrer: 14417356
Notable recruitment policies: Rank 70+ only; must join the Discord
Last Guild War: Jan N/A | Mar DNQ | Apr [B] 2W-3L : 3(0) | May [A] 0W-5L : 6(0)

Guild name: Fleet
Link: http://game.granbluefantasy.jp/#guild/detail/599992
Profile ID referrer: 8817744
Notable recruitment policies: None
Last Guild War: Jan N/A | Mar [B] 1W-0L : 1(1) | Apr [A] 0W-5L : 3(2) | May [B] 0W-5L : 1(0)

Guild name: Beafriends
Link: http://game.granbluefantasy.jp/#guild/detail/940700
Profile ID referrer: 6683855
Notable recruitment policies: Must love Beatrix
Last Guild War: Jan N/A | Mar N/A | Apr DNQ | May DNQ : 0(0)

Guild name: BellaBarca
Link: http://game.granbluefantasy.jp/#guild/detail/977866
Profile ID referrer: 14979189
Notable recruitment policies: None
Last Guild War: Jan N/A | Mar N/A | Apr N/A | May [B] 1W-4L : 2(0)