I don't think there can be such a thing, because I think OTL has pretty much explored the phase state of possible ideological concepts; the only question is which ones became pseudoreligions that set the world alight (communism, fascism, etc) and which ones failed to inspire and lay mouldering on a shelf or in an irrelevant group of 300 nutters (syndicalism, social credit, etc.)
I hope that doesn't make me sound like that guy in 1900 who said that everything that can be invented has been invented.
I have to disagree with you there, Thande. I think that there are massive Swiss cheese holes in the areas that humanity - even including all the way back to pre-ancient times - hasn't explored, it's simply hard for us to think of them because of the twin factors that philosophies tend to be a reaction to circumstances (and so it's hard to think up new philosophies that have absolutely nothing to do with the world as it is now, or has been in the past), and also that we are somewhat preconditioned from childhood to look at all philosophies from the perspective of that which we know - i.e. we examine them on the sliding scales of political and economic freedoms and assume that they can be fitted into our current left wing v right wing political standpoints.
It's probably true that, to a lesser or greater degree, we have explored virtually every type of universal democracy and centralised hereditary autocracy, but those are just some of the ways that society could go - it's just that many of the alternatives may require a very, very early POD. Consider some of the following (and I will admit that these took me some time to come up with, as I myself found myself just thinking of different democracies over and over again):
How about a situation where the military (and I'm thinking something closer to the Roman military than the present day) has control of all political and perhaps even economic institutions? Say, where a company controls a town, a regiment controls a county and so on, and so the Commander-in-Chief is considered head of the government. In fact, in some ways it's closer to Roman-era tribalism. In this philosophy, the merchant class would probably consider itself to exist primarily to equip its garrison and secondarily to feed and clothe civilians, and there would probably be a kind of blurry assumption that everyone was in some way a part of the military, they were just more reservists with professions than front-line troops. Also, the distinction between officers and rank-and-file would probably be pretty weak as this would likely form this society's version of social mobility - an aspiring soldier who does well would be likely to be given a leadership role after a while rather than being penalised against for not having joined at officer rank.
How about a society where a caste system exists, but rather than being a pyramid structure where those who work the land come last and those who own land come top, each caste is considered nominally equal, and being a merchant is just as important as being a politician? I'm picturing a world where the "governing caste" is a group of Greek-style philosophers who spend most of their lives in debates, asking questions about the nature of the world and of humanity, and whom debate in large gatherings and vote on resolutions for how the society will proceed - who to go to war against, what buildings to build, etc. It could even be that those who control the money are not those who control politics, so there is a caste of administrators who decide how much money can be spent on renovations, how much on salaries etc. It may not prove a very strong society, but it's an idea.
How about a form of state corporatism, where everyone is assumed to be the employee of the country, and wages are allocated from public funds according to what job you do and how long you have been in it? All money earned from sales would be paid to your local tax-collector who would then give you your "fair share" from it, regardless of how much you have actually sold (although underperforming I guess would be punished financially) and thus operating for profit simply is not considered as everyone assumes that it is right that extra money made be donated to the state for the betterment of everyone. The incentive to work hard would not be to build that nicer house and expand your farm, it would be to see your local town and further up, your capital city, grow bigger and more opulent, and from there the benefits would pass downward. Of course, more money in the state coffers would also mean bigger salaries for the workers.
Or finally, how about a society based on right of power? The kind of thing where anyone can challenge for a leadership role if he can do something like best the incumbent in a fight, or prove he has more followers, or manipulate away the incumbent's power base, or become wealthier or something. Sure, it would be a highly volatile and unstable society, but such unstable societies have been known to develop in large powers that are local hegemons and have no real competitors, as they rarely get punished for their wobbly control structures and moments of weakness, until it all comes crashing down in a monumental way. I guess in this scenario, those "born weak", or bested and therefore publicly humiliated etc, would be forced to do the menial work and I guess there would need to be a system of reputation and of peer acceptance to stop everyone just queueing up each day to fight for the right to rule and hope to just get lucky. I was going to suggest a kind of Sith Empire-style system, for anyone who knows the background of Star Wars, where basically if you could kill your superior then you legally could claim possession of all their belongings and titles/offices, but honestly I always thought that that system was nothing other than a perfect way to depopulate an entire society - there would need to be a rule stating that anyone who killed another person in a challenge was themselves killed or exiled to prevent one big massacre going on.
I'm aware that some of those ideas are not only sketchy but arguably poor ways for society to go, but I'm just trying to demonstrate here that there are plenty of ways of assigning power other than having democracies or monarchies controlling everything, and simply limiting how much of a say the average person gets.