Germany. The outer borders are not so much different from OTL, but still there are some differencies...
After World War II, the allies decided to draw the new German-Polish border not on the Oder-Neiße-line, but along the Bober river in the south (instead of the area near the Czechoslovak border, where the border turns southwest-wards - along the border between the Silesian counties of Löwenberg and Hirschberg), on the borders between the Prussian duchies of West- and East Sternberg and between the Königsberg/Neumark-county in the west and both Landsberg- and Soldin-counties in the east, as well as between the Pomeranian duchies of Greifenhagen in the west and Pyritz in the east, (while the area of Neumark, Mühlenbeck and the shore of the lake Madüe from the Greifenhagen-county will be ceded to Poland) as well as finally between Stettin(-Altdamm) and the Naugard-county, with addition of Lübzin (belonging to the Naugard-county) remaining German. Further the new German-Polish border is drawn on the island of Wollin, at the narrowest point between Swinemünde-Ostswine and Misdroy-Liebeseele.
This includes the following cities and towns east of the OTL Oder-Neiße line being kept by Germany (only places with a population above 10.000 are listed - populations as of December 31st, 2009):
Swinemüne - 40.749
Pölitz - 51.052
Stettin - 419.435
Küstrin - 25.760
Guben - 43.679
Sommerfeld - 13.304
Forst - 25.364
Sorau - 29.280
Kohlfurt - 10.290
Penzig - 10.004
Görlitz - 88.376
Lauban - 19.273
There are also parts of Sagan, Sprottau and Bunzlau, all on the left bank of the Bober river, but these have a population under 10.000.
Please also note, that all of German-speaking Luxemburg (including Arel) became part of Prussia in the early 1830s after an agreement with the Netherlands, plus - after World War I - the border to Denmark has been drawn after the Tiedje-line, instead of the Clausen-line and all German-speaking areas of Eupen-Malmedy remained German after World War I.
The allies also decided to draw the borders between the occupation zones a bit differently, as well as these of the states (Länder). Schleswig-Holstein gets the former Mecklenburgian county of Ratzeburg. Lower Saxony has been formed by the former Prussian province of Hanover, the city of Bremen (which became the capital of Lower Saxony), the state of Oldenburg and the state of Brunswick, instead of the area north of Helmstedt, including Wolfsburg - this area, now a part of the Soviet controlled east, from 1949 on became a restricted military area, almost all the population had to leave this place. Wolfsburg itself including the industries have been mostly demolished and then got left to itself. Also the Lower Saxons had to abdicate the Braunlage-Walkenried part of former Brunswick state (which stayed West German in OTL) because it was given to the Soviet occupation zone.
Westphalia-Lower Rhine (Westfalen-Niederrhein) have been formed by the Prussian province of Westphalia and the northern half of the Rhine Province, the state of Lippe, both parts of Schaumburg and the northwestern half of former Waldeck. The Brits decided to choose Dortmund as a state's capital.
Without France being part of the occupators, the Americans could realize their dream of a "Greater Hesse" - but with minor border corrections with the Soviet occupied Thuringia, also the Americans allowed the Franconians an own state, which also got the formerly Thuringian Heldburg and Sonneberg. Because there could not appear an agreement about if Nuremberg (Nürnberg) or Würzburg should be the capital of the new state, the US helped on the decision and it was agreed, that Bamberg gets the capital status, although being quiet smaller than either Nuremberg or Würzburg.
Rhineland-Palatinate has very soon renamed to Moselland-Palatinate (Moselland-Pfalz), because the rhine is firstly just partly a part of the state and secondly when, mostly just on the border of the state, while the Mosel river is a significant part of the state. Also the capital has been removed from Coblence (Koblenz) to Trier in the early 1950s. Baden can keep its status as an own state and Württemberg(-Hohenzollern) gets the formely Bavarian district of (Upper-) Swabia and can form their southwest-state. For this, Ulm has been reunified after centuries (Württembergian Ulm and Bavarian Neu-Ulm) and became the capital of the new state. Bavaria, now reduced to its main linguistic unity is now renamed from Bayern to Baiern in German.
Here are the official abbreviations and capitals of the German federal states (Bundesländer):
SH - Schleswig-Holstein (Kiel)
MV - Mecklenburg-Vorpommern (Schwerin)
NI - Niedersachsen (Bremen)
SA - Sachsen-Anhalt (Magdeburg)
BB - Brandenburg (Potsdam)
WN - Westfalen-Niederrhein (Dortmund)
MP - Moselland-Pfalz (Trier)
HE - Hessen (Frankfurt/Main)
TH - Thüringen (Erfurt)
SN - Sachsen (Dresden)
LZ - Lausitz (Cottbus)
FR - Franken (Bamberg)
BA - Baden (Karlsruhe)
SW - Schwaben (Ulm)
BI - Baiern (München)
Berlin and Hamburg are Federal Cities (Bundesstädte) and include only one municipality each.
And yes, the birth rate has been a bit higher than in OTL, so that Germany has that number of inhabitants in this TL.