Thanks: I'm less familiar with this house (since they don't really make much news). But I was aware that they've been doing a darn good job of maintaining consistently high marital standards, over the years. Certainly better than the other reigning houses, and even some deposed dynasties.
Before World War I, they had one of the lowest standards -- accepting members of even non-mediatized nobility as *equals* for marriage. But they haven't lowered their standards to accept, at large, untitled commoners (of course, there are exceptions, such as Prince Maximilian, second son of the sovereign, who married Miss Angela Brown).
There is nothing like retaining a reigning status, to raise the stock of a dynasty: just consider all the houses that got deposed, as a result of the two 20th century world wars ...
Jane says that she is "restricting the definition of *equality* to the first two sections of the ALMANACH DE GOTHA (meaning houses that are sovereign, formerly reigning, or mediatized)."
According to that definition, the last Liechtenstein example would be the 2000 marriage of Princess Marie (daughter of Prince Eugen) to Count Ferdinand von und zu Trauttmansdorff-Weinsberg.