Ok, I'll go for three wild possibilities and let the GM select. I'll be a less prolific player than before, but maybe I can withstand the chill tempo of today's forum games.
P.S. I promised to be less prolific. Haha. Reading my history book of a submission, I think some things never change. I can't write short.
1. Third Burmese Empire (Konbaung Dynasty). Color: dark green. Claims: modern Mynanmar + most of today's northern and central Thailand.
Just as historically occurred, the Konbaung Dynasty rises from a humble village chief Alaungpaya in 1752. As OTL, he fights against the freshly restored Neo-Ramanic State of the Hanthawaddy dynasty, taking it down and replacing with his own Alompra or "Hunter" lineage. His descendants expand the realm even more, eventually invading and conquering most of northern Siam. The Third Burmese Empire's trajectory changes in 1776, when prince Signu Min is crowned and demobilizes the army bogged down in the treasury-draining campaign. The first non-military-minded Konbaung ruler, Signu Min consolidates the patchwork state his great grandfather had conquered. An arbitrary and soft ruler, he ends up heading for a fateful pilgrimage and being dethroned by his previously exiled cousin Prince of Phaung, Maung Maung. Unlike OTL, Maung Maung catches a wind of a quickly slapped together plot by his militarist uncle Prince of Badon, and when he uncle rushes the second coup, Maung Maung and his guards catch him and execute. This prevents the second stage of the Konbaung expansion under who will become known OTL as King Bodawpaya. The slowdown doesn't weaken the dynasty, as Phaungkhaza Maung Maung proves to be a capable meritocrat with a good sense of balance between expansionism and organic work. He starts a series of reforms and a military westernization campaign that OTL took until King Mindon to enact (far too late for forcing back the British), and due to his prolonged reign, the later, more militarily-minded kings would concentrate the Third Empire's reformed warmachine not on a westward expansion into the British-held Manipur and Assam, but into the lands of the still standing Thonburi Kingdom of Siam, evading the conflict with the British altogether. With that, by the 1820s, the Third Burmese Empire is a dynamic, prosperous, and surprisingly centralized kingdom, starting to spread its wings in Indochina.
2. High Collegiate of Transvolga and the Urals. Color: greyish green. Claims: The Don and Volga river valleys, the Urals, and Siberia all the way to the Amur river.
As per OTL, Yemelyan Pugachev raises the flag of one of the most successful peasant rebellions against the Tsarist rule in the Russian history in 1773. He claims to be the escaping true Tsar, ex-husband of Catherine the Great, Piotr III. Savvy, but illiterate, he manages to build a surprisingly complex and well-functioning bureaucracy and army structure when the rebellion picks up steam, mimicking the intricate structure of the true Tsarist state (as OTL). His fortunes get saved by an ill-executed assault of the city of Kazan in July 1774. His troops fail to infiltrate the city and get called out to the camp. This divergency prevents a night of drunken celebration, so when General Michelson's royalist reinforcements from Ufa approach the Arsk Field, Pugachev's irregulars are disciplined and well-rested. Michelson's defeat eliminates the only big Tsarist army in Tataria and Bashkortostan, essentially granting the rebels control over the industrial towns of the Urals. Panicking, Catherine the Great ends up redirecting her best general Pyotr Rumyantsev against Pugachev, and the "soldiers' general" ends up saving Rostov against Pugachev's offensive. Pugachev is killed in the battle by a stray cannonball, seemingly beheading the rebellion. This, counterintuitively, reverses the fortunes once again, as Rumyantsev gets "triumphantly retired" by Catherine II's known favorite courtier, the ever-corrupted sychophant-in-chief Prince Potyomkin. The latter hopes to get fame and influence by mopping up the headless rebellion while it's still worth the Tsarina's grace, but what he fails to understand is that Pugachev's High Collegiate actually functions much better without the self-aggrandizing, illiterate ex-ensign to lead it. Putting away all intrigues for the sake of survival, the Colleagues (most of them ex-officers of the Imperial Army or ethnic nobles with political capital in the diverse region) reorganize the army, properly discipline it, and staff with the newly freed, but highly motivated ex-serfs. The de-industrialization of the Urals (started as a campaign of freeing factory serfs) is reversed for the sake of winning the war, and soon Prince Potyomkin repeats the fate of his historical doppelganger Marcus Lucinius Crass by blundering in a Carrhae-like battle in the Upper Don steppe. This reignites the rebellion in Ukraine and Central Russia, but the still firm Tsarist regime drowns the minor rebellions in the sea of blood, eventually alienating itself from the commoners and transitioning to a proper Baltic German dynasty. With the (open) Ottoman and (secret) Swedish financial help, the High Collegiate survives a renewed counteroffensive by the reinstated Rumyantsev, albeit at the cost of losing any hopes of reaching Moscow or even its vicinity. With the rebellion seemingly unending and the support among the fellow monarchic regimes of Europe notably lukewarm, the "enlightened despot" Catherine II ends up cutting her losses and securing a shameful armistice shortly before succumbing to palace coup that bring a hysterical Prussophile Paul I to power. The Romanov Empire remains in control of its core European territories, but forever transforms into a truly syncretic Germanized state ruling over the illiterate and alien Russian, Ukrainian, and Belarussian population. Meanwhile, the High Collegiate, equally claiming "all the Russias" as its core, rules over the Volga-Don breadbasket, the industrial heart of the Urals, and the vast tracts of Siberia as a much less enlightened and more diplomatically isolated precursor of the Jacobin revolutionary state.
3. Tây Sơn Dynasty of Dai Viet. Color: yellow. Claims: Today's Vietnam and Laos, the island of Hainan, southern parts of Guangxi, plus part plus some islands in the Malacca region.
Originating from the Tây Sơn ("western mountains"), the historically accurate dynasty is founded by three brothers rebelling against the Nguyễn lords of the North. Strategically-minded bandits, they form an army of unprecedented complexity and operational know-how for that historical region. Just as OTL, the Tây Sơn Dynasty leads a series of brilliant campaigns against the northern Nguyễn lords and the Trịnh lords of the south, until eventually conquering them all and uniting the entire Vietnam. Just as OTL, they become targets of a Qing invasion, fighting it off and building an impressive warfleet in the process. The dynasty's most long-lived ruler, Nguyễn Huệ, conquers parts of the Siamese Thonburi Kingdom and secures his line of inheritance, while preparing an invasion of the notoriously disloyal southern provinces of the Qing Empire, expanding the spy network and reinforcing his fleet with the avidly anti-Manchu Chinese privateers. He doesn't die as early as he did OTL, and his invasion goes according to the plan, eventually hitting the wall of Chinese unending resources, but not before de-facto securing the Miao and Min lands. Just as OTL, the Nguyễn lords attempt to return after Nguyễn Huệ's eventual demise with the help of French adventurists, but this time the Tây Sơn heir apparent is better prepared for his duty, upending the Nguyễn dynasty's unlikely resurrection. Besides, the Tây Sơn conquests in Southern China attract the attention of the British (TBD: Americans/Dutch), who greedily eye for an entrepôt into the vast Chinese market and are happy to prop the Tây Sơn against any enemies for a while. Still economically backward, the dynasty is firm and dynamic, and its highly centralized military and fleet are rapidly modernizing, leaving possibilities open for a full westernization of the Vietnamese society and economy.