I think alot of people are missing the point with some of these sliders in that whats "best" is entirely dependant on what country you are playing...Russia (as common sense would indeed lead one to think) does well with high serfdom...keeps those stability problems down, and those waves of 50,000 infantry do fine on rampaging thru enemy territory assulting and such. On the other hand, playing the Dutch my slider started max free subjects and I just left it there...The production is a nice bonus, morale always helps some, and Stability isnt a big problem as I'm mainly colonizing not conquering and thus my provinces are mostly Dutch Reformed. Same goes for most of the other sliders--Narrow-minded is great if your Spain and need the extra colonists, missionaries, and stab, but if you are a small asian nation you'll need every advantage you can get to keep up in tech and the bonus for innovation is very significant. Aristocracy is great if you're Poland, but a Free-trade, Plutocratic, Reformed Dutch state can bring in amazing trade revenues, etc. etc.
BTW side point, but if anyones jaded with "too easy" majors but finds playing a minor with no events and leaders lacking in flavour, recycle that old game save you quit after 150 years into a very fun game as the Dutch. I was playing Denmark thinking it might be a fun game with lots of events, but after I got an explorer in 1520ish and established 4-5 colonies it was instantly looking way too easy...load the game as Spain, create the Dutch as vassals, save and reload as the Dutch...a good challenge trying to catch up starting with 3 provinces (in my game) against nations that are already 1200 points ahead of you, not to mention the fun/frustration of trying to compete with the monster you had created before. My former Denmark was ahead in all techs, richest country in the world, and was continuing to expand as the AI. Finally frustrated with their level 7 trade merchants frustrating my efforts, not to mention their runaway VP total, I manuvered into an alliance with Sweden, and had one of the funnest (albeit frustrating) wars ever in ALOT of playing EU. With 9000 manpower a year I had alot of trouble competeing with their limitless coffers and endless cavalry reinforcements, within the first 2 years my holdings in the carribean were burnt/seiged easily then they started moving in on my stuff in S America and S africa, wasn't looking good at all. Back on the continent, we had some early successes lead by Maurice of Nassau, but once he started pumping out huge armies of 40k-50k (his land and naval was 3-4 above anyone else's in the game which wasnt fun either), the tide turned climaxing in a large battle where Maurice fled a tad too late and my main army of 37k was defeated and utterly destroyed by the massed Danish cavalry
things weren't looking promising at all. The Swedes were contuinally thwarted by the danes clever defensive tactics, and the fact that for some stupid reason (grrr!) the swedes would build 80k armies with Gustav Horn but Adolfus II wandered around with 9k men and couldnt even conduct a proper siege. For once tho, navy proved crucial and with the super-admiral the Dutch get (forget name but hes like 5-6-4 or such very nice) in the vangard we swept the danes from the seas and were able to thus win the battles in the colonies, while hordes of Hessian mercenaries stalemated him on the continent, while I sent detachments by sea to follow around Gustav Adolf in support whereever he went
We won finally, I took 2 provinces and gave 2 to Sweden in the peace process (its a bit tough being reformed in many ways I think I was the only nation active in the game with Reformed before Sweden in an odd move decided to go Reformed in an event thus providing part of the rationale for the alliance.) But... 1635...Denmark is still a good 900 pts ahead and very strong, worse yet Austria is huge also and 1200 pts ahead...Dutch are not a good warmongering nation being reformed and only dutch as culture, this looks like a game that might prove fun all the way til 1819!
More good major nation challenges to suggest:
Poland starting in the 1600's scenario: nation starts poor with no realistic possibilities to colonize (at least if you remain catholic which I of course do, I never change religion unrealistically just to get bonuses), and few areas offering easy expansion, and just when you get the economy and such in order and move on your neighbors the dreaded Librium Veto event, possibily one of the worst events in the game
Sweden 1700's: The joy of starting alone at war vs Russia Poland and Denmark
Really any major in a game that got boring, try reloading as a faltering major and see how easy the AI when it has your old position: sliders set all nice, techs all above yours, swimming in cash and manpower...The battle AI is alot better than in EU I, so if the AI is superior in all these categories you have to really scramble!