I'll go ahead and claim that most of these books are pretty dry these days. Historically significant, yes, and everyone should definitely know of them and what they're about. But reading them probably won't make much of a difference to your life. The same information can be found in other places these days, in forms that are more comfortable for the brain to digest.
Reading large works like these may stimulate your thinking much more than getting the same information in a shorter format.
If your reaction to reading The Prince, for example, is to go off and read other historical analysis of the many obscure conflicts he references, and discussions of the extent to which certain comments may have been intended as satire, then it might make a stimulating starting point for study. If you're simply looking to gain insight into the motivations of people in power, then you'd be better off reading an article-length summary of his key points and prioritising on to short-form content about Westphalian states and the limitations of democratic processes. Ultimately, you'll learn more relevant lessons from that than you would from Machiavellian observations on the castle of Milan causing more trouble for the Sforzas than it saves or the susceptibility of the Spaniards to cavalry and the Switzers to close combat.
If you want to learn about markets, capitalism and pricing, then economists of all stripes will agree that the Wealth of Nations is commendably broad and readable but very outdated in its examples; many of the features of modern capitalism and the entire theories behind modern anticapitalism simply hadn't been invented then. If you want to learn that "capitalism is an economy of greed, a force of nature unto itself", it's a strange, rather agrarian-focused introduction that won't give you any insight into modern debates about welfare or Wall Street.