Great answers so far. Let me throw a few other ideas into the mix:
First, it's interesting that you saw a house you really liked. Some people have--don't know what you'd call it--maybe a fear of making a choice, so they never, ever see a home that's right for them. So, good. You know that there are homes out there that will work well for you.
Second, if you haven't already done so, make up a list of things you want in/regarding your home. Make three categories: "Must Have," "Very Important to Have," and "Would be Nice to Have." In the "Must Have" category are things that, clearly, you must have. This list shouldn't be too long, because, as I'll mention in a moment, a lot of things are fixable. Next are the "Very Important to Haves." This is what turns an OK home into a desirable home for you. And, finally "Would be Nice to Haves" shouldn't make or break the deal--these are like icing on the cake.
Review the houses you've seen, as well as just thinking about what you need and want, and fill up these categories. Make sure you keep a copy, but also give one to your Realtor. Only visit the "Must Haves," and try to limit your viewings to those that have most of the elements on "Very Important to Have." Don't worry about the "Would be Nice to Have" category...at least not yet.
Now, remember that lots of things are fixable. OK: You must have a home with two bathrooms. Or do you? If you could add a second bath for $5,000, and could buy a 1-bath house that in every other way met your needs for $10,000 less, then maybe that 1-bath house should be on your list. So, you might move "2 bathrooms" from "Must Have" to "Very Important to Have." Do you demand a garage? Well, if it has a carport, you can probably convert it to a garage. And so on.
In a related area, one problem that many buyers understandably have is that they're not able to visualize the house in a different way. A surpising number of real estate agents aren't, either. That's why home staging has become so popular. Not only does it clean up and declutter, but it helps buyers imagine themselves in the house, and how they'd use certain rooms. I'm not sure what's turned you off with those 50 homes you've looked at, and I'm not trying to persuade you to settle for anything less than you want, but make sure you look beyond the current state of the house and imagine what reasonably you could do with it. Some homestagers are even getting into "virtual home staging," creating an interactive, 3-dimensional walk-through of homes, to let buyers imagine what it could look like. It's also easier and more economical than an actual staging.
Finally, if it'll help, consider enlarging the listing price parameters. If you're currently looking at houses in, say, the $120,000-$140,000 range, ask to see houses priced up to $150,000. I'm not suggesting you necessarily pay more...or that you pay any more than you're comfortable with. Put in an offer that works for you. So, if your absolute top amount that you can spend is $135,000 and you've been looking up to $140,000....okay, look at $150,000. Still, make those offers at what you'd be comfortable with--say $130,000? Or even less? Your odds of being successful may be less, and you won't win as many popularity contests with real estate agents, but you don't know what a seller will take unless you make an offer.
Hope that helps.