I'm sorry, I didn't realize that there were so many libertarians here.
Now I feel like a bit of a jerk calling them all crazy. I don't even remember any of their opinions ever seeming that crazy, at least from the list of the "sane libertarians" given above.
Like a lot of political groups, but maybe even more than most, libertarians have a bit of a problem with their crazy people being very audible while their reasonable people are quieter. There are also a number of varieties of them which have little in common other than shared political beliefs.
One of the more common types in geeky locations such as this one is the type that attempts to build their views of how society should work by defining axioms (e.g. a set of rights including fairly absolute property rights, rational economic behavior, and so on) and trying to deduce everything from those axioms. This is a great way to make a self-consistent model, but what it produces is a model. Models are always oversimplified relative to reality and may not correspond to reality well at all. But if you try to argue with them, they'll respond with something that makes perfect sense within their framework but still doesn't match reality. It's very hard to convince people their views are just a model if they can't think outside their model and have staked a lot of their identity on it.
Common sub-types include most Objectivists and most anarcho-capitalists. Among the anarcho-capitalist writers, Rothbard is worth reading. He concisely shows both the internally consistent reasoning and the severe limitations in actually matching reality that appear in that sort of approach. I especially like his explanation of the business cycle. It shows some insight into some aspects of them, but his theory is seriously flawed because it doesn't take enough about how actual economies work into account. His essay on pollution is also interesting - here he attacks polluters as violators of property rights who should pay restitution for damage they cause other property owners. When it comes to enforcing this, he becomes a lot less coherent. A collective issue like global warming, where some types of economic activity cause uncompensated and impossible to quantify damage to much or all of the planet, will simply break this ideology, which is why you'll see a lot of global warming skepticism or at least minimization among this lot.
There's also a completely different type of libertarian - the variety commonly associated with rednecks. These libertarians tend to be white, rural or suburban, and working to middle class. Here, you'll see a few positions commonly labeled conservative, like opposition to immigration, a strong emphasis on gun rights, sometimes support of the death penalty, sometimes opposition to legal abortion (defensible if you view a fetus as a person with rights), and a few other things. These are combined with "hands-off" views on the majority of social issues - they tend to take a dim view of government interference in issues of morality and would tend to think the state should play no role in any kind of marriage (straight, gay, or otherwise), almost always support drug legalization, usually oppose military involvement in foreign countries with no obvious connection to national self-defense, etc. Some proportion are also racist, but they rarely think they are and would generally be perfectly fine with a black person who happened to act and believe the same things they do and live in the same location.
A third type can be found in what I call the pro-business variety, which use libertarian ideology to make political points but isn't as opposed to government policies that happen to benefit business interests, such as "free trade" agreements that turn out to contain a lot of protectionist measures that benefit the stronger parties, fire-sales of government assets to existing large corporations, massive deregulation of financial markets while ignoring well-known systemic risks, and flat taxes that turn out to be regressive when you consider capital gains and other things that they would usually exempt (or sometimes outright regressive but simple taxes, like the FairTax, which is a 30% sales tax on just about everything), to name a few. This is the type that bridges the gap between the ideologues, who supply the reasonable-sounding arguments, and real crony capitalists, who are actually at the government feeding trough and are generally despised by earnest ideologues. Most of what the Cato Institute produces are in this category.
Of course it's a lot more complicated than this - there can be overlap (e.g. GW16 and Ron Paul are between types 1 and 2, and the more doctrinaire neoclassical economists are between 1 and 3) and there are other groups as well. But that's three groups of self-identified libertarians in partially-formed nutshells.
Most of the people Cutlass was referring to may not be seen as "real" libertarians by the more ideological types. They generally support market-based solutions where practical, while still allowing government intervention where it is clearly preferable. For every ideologue of any given ideology there are usually several people who lean in the direction of that ideology but will use other ideas in cases where this ideology breaks down.
...that was long-winded, and I've only scratched the surface. Concision isn't my strong suit.
