Any good reasons to be affiliated with any specific nation other than wanting Refresh from Sibyl Scarf as Windurstian or Regain from Republican Platinum Medal as Bastokan?
With Bastok you gain access to best gil to conquest points per unit time exchange rate with the Rank 5 Musketeer's Gun.
It NPCs for 17.3k or there abouts, while being buyable when Bastok is in 1st place for 16k from rank 5.
Since Bastok generally rides down to 3rd place, you gain enhanced Conquest Point gains, particularly in Locus or Apex zones Bastok doesn't own, allowing you accrue a ton of conquest points between 1st place weeks, meaning you can make more gil sometimes without as much hassle, since Windurst and San d'Oria offer nothing with an equivalent exchange rate beyond the rank 3 2-handed weapons (which take 3x as long to NPC into gil).
Bastok Mines also boasts the only one of the three nations with a Survival Guide next to an Auction House and HP. A minor time saver that's being phased out soon, supposedly when they combine Survival Guides into HP warps, it's long been a great spot to leave as your HP, as it's also super close to Mog House aaaand a Chocobo Stable.
Bastok also has the most NPCs involved in multiple storylines and expansions. Volker and Zeid were on the team that killed Shadow Lord in canon. Cid is heavily involved in Chains of Promathia. Zeid is heavily involved in Rise of The Zilart. Naji and Ayame feature in some ToAU missions. Serpent General Zazarg is Bastokan, and is the Praefactus for the 4th Division in WoTG, being apart of The Battle of Jeuno. Degenhard is Bastokan and was once Maat's original sparring partner under Atori-tutori. Jeuno itself was started by Bastokers, and as such, Maat was originally from Bastok.
The jobs Warrior, Monk, Ninja, Samurai, Dark Knight, Scholar, and Dancer have their artifact quests mostly/partially rooted in Bastok. Norg has ties to Bastok.
Bastok isn't afraid to get down and dirty when it comes to warfare, even employing chemical weapons against the Sahagin. Bastok invented firearms in The Middle Lands. Cid is the first non-Armathrwn Society member to make heads or tails of airship technology, and produce airships.
Galkas are cool and Hume ladies are hot. Bastok also features several varieties of NPC only humes, including some more elegant refined hume lady NPCs in dresses and hats.
Bubbly Bernie is right outside in South Gustaberg. The Drachenfall in North Gustaberg features a lot in the pre-character selection scene, and is a very bad *** waterfall.
The WSNM quests, "The Weight of Your Limits" and "The Walls of Your Mind" are presented to you by Galkas from Bastok. The quest, "What Price, Loyalty" is from Bastok [S]. These are the coolest names for quests ever conceived.
Bastok is the only nation that has its own soldiers nodding to the idea that it's ok to hate your government, while San d'Oria and Windurst kneel before a (noble)monarch and a theocrat(she is a lame duck dictator, it turns out). Though it's mainly hate the senate, and begrudgingly respect the *** in charge(president).
Bastok's flag is blue, a water wheel surrounding a shield, surrounding the spires of industrial buildings. While the actual architecture and picture is quite different, the cave painting of Amaurot ablaze in FFXIV sort of calls back to Bastok's flag design. a taller building in the center of shorter ones.
Bastok has not forgotten about religion. Though Bastokers are not known for their piety, they do keep an alcove in their capitol directly in the center between the elevators of the Metalworks. It serves as Bastok's temple to The Goddess, though no organized religious ceremonies take place there.
Bastok has great natural defenses. Flanked by mountains and the sea, the only reasonable way to assault it is by coming through river from Palborough Mines or Korroloka Tunnel.
Bastok is Bestok!