Tbh,almost any nation will sound good,if all the surrounding players just go inactive. That is how I managed to win as South USA,because Central USA got inactive. Another example is France. Once everyone nearby is inactive,you dont have to guard your borders,because bots usually do not invade you (Unless they are Elite AI). I was once tempted to say that France was a really good nation,a few months ago,but then I realised that France is really bad,because France has only one lumber province,and too much iron that you wont need anyway.
What tier do you put Germany in? I have always viewed Germany as a shitty nation. Low on wheat,iron,lumber,oil,and too much coal overload that wont be used.
What do you think about Sweden? Sweden,situationally is REALLY good. Like,I would rate it S tier in certain cases. If you are Sweden and allied with Norway/Finland (or maybe both),you are almost guaranteed to win,as long as your ally is at least average. If you are allied with/have conquered Finland,you can invade North Russia or Central Russia for oil. Bonus points if you catch them both fighting.
If you dont ally with Norway,another option is to invade Norway the moment you start the game. Their capital is right on the border,many of their cities are also on the border as well,and Norway is a very 'thin' country. Thus,you can easily divide Norway into two sides. Most of the time I have seen Sweden and Norway in a war,Sweden wins 80% of the time.