There's a list of things in order which MUST be followed, or else they won't be a SO at all period.
1: They must be intelligent enough to maintain an intellectual conversation with me. If I can't talk to them about my ideas, theories, and so on, then I will feel unloved, get annoyed, and eventually just not like them anymore. I must be able to share with them the things I find interesting, and to do this they have to be able to comprehend them on at least a remotely similar level. It's exceptionally rare to find anyone who can match me on this level, so being 'close enough' that I can at least explain it to them is good enough for me. They don't have to be smarter, or identical in the brains category, but they have to be close enough to hold a discussion where they actually have any clue about whot I'm talking about.
2: They have to be willing to work for it. Check my post on infidelity if yeu'd like a better view, but the short version is... I will not play guessing games, or hide my heart. Yeu have every opportunity humanly possible available to yeu to either directly give me whot I need, or to try to help me get it indirectly. If yeu don't care enough to help me in the slightest, yeu will loose me.
3: They must do the same to me as I do to them in #2; this's normally called 'communication', but a bit more specified. I don't do guessing games well, or just 'magically' know whot they're thinking... I'm a little bit ... slow... in certain social situations, and emotional ones. I need to have things spelled out clearly to me at times, with no analogies I may misinterpret. Explain to be clearly whot I need to do, and whot I'm not doing, and I'll work with yeu to cover it in one way or another. If yeu refuse to tell me when I didn't do something yeu expected, or didn't tell me I did something wrong, I'm just going to keep doing it. I need to know to fix my problems; I highly value self improovement, but I can't improove whot I don't know is broken.
4: Emotional growth, I don't handle my emotions nearly as well as I'd like... I pretty much need someone who's able to grasp this concept and work with me on it. If yeu expect me to be the most perfect woman ever well... it's not really going to happen that way. I need alot of patience to deal with me, and someone who can tollerate helping me a step at a time on the way of improoving myself in that regard. If yeu can't tollerate the fact that I am frequently completely dumbfounded on an emotional level, then yeu won't be able to tollerate me in general as a mate for any length of time.
5: At least SOME sexual compatibility. It doesn't have to be perfect, there's ways around some incompatibilities, as there's going to be some situations eventually that're guaranteed to not mesh perfectly, no two people will ever have the exact same tastes (ask two people to choose the toppings for a pizza... yeah yeu get my point). However, there has to be SOMETHING there to work with as a baseline, if there's zero compatibility then it won't last long term unless they're willing to accept that I will go elsewhere to get it if they are either unwilling, or unable to provide. We all have our needs, in many different areas, and they are NEEDS because they MUST be met. If yeu can't directly provide, then work with me to find a way to indirectly do so. If we're so totally different to the point of not wanting anything even remotely the same EVER, then by default, it's not going to work.
6: At least vaguely descent looks. I can tollerate them not being the 'zomg it r teh stud!', but I don't want to feel nautious when I look at them either. If I can't even give them a hug without feeling like I'm going to be ill, then it kind of makes any sort of physical intimacy go down the drain fast... I don't put much stress on physical appearance for the most part though, it's nice to have, but that's all it is... 'nice to have'. If yeu look great, but can't meet any other of the 'must have' qualifications, then yeu're useless to me. I will never be able to love yeu on any level. Yeu don't need to be the best looking in the world, but yeu have to at least be tollerable. A little overweight is even alright, as long as it's not like "lol they need to knock down walls for me to get to the hospital" which's just... scarry.
7: gender's not a big deal but I'd prefer a guy. I consider myself... 'technically bi, but mostly straight'. Primarily, I prefer the mind, emotional aspects, and pretty much everything about guys better... though honestly I do have a minor preferance for a female body because guys are so... generic, and bland. No curves really, too bulky and such, I prefer agility over strength, muscles don't really do anything for me. But the thing is, the physical is only a minor thing, I'd far rather have someone who matches my ideals of a perfect mate in every other respect, if I can't get along with them on a level where I truly love them, then the body doesn't even matter. The vast majority of females do not meet my previous qualifications, and therefore never get this far. I consider it mostly "I pretty much am looking for a boyfriend... if I just happen to find the perfect one, and it just happens to be a girl, I'll go with it anyway, love's blind, yeu can't choose who yeu love really, just go with whot's right. If yeu find that perfect person, take it, regardless of anything else". I try to be open about this, but in practice, it's not a very likely chance due to many factors. Women just generally aren't of the mindset and emotional type and such that appeal to me; if I DID find one that perfectly matched, I'd not hesitate to go out with her, but it's unlikely I'll ever bump into that situation.
As with everything else... there's a great deal of minor things, but seriously, they don't matter on any grand scale. If yeu meet these criteria, in descending order, then yeu will likely meet my concept of the ideal significant other. If yeu have any gaps in any of these, as in totally missing... then yeu won't get anywhere. Yeu HAVE to be able to match these 'must haves'.