The Communist Manifesto

I think it's pretty good. It's pretty polemical and lays out the political goals of communists, it doesn't really get into Marxist philosophy and the methods in which Marx comes to his conclusions though. I'd probably recommend "Socialism: Utopian and Scientific" as a better introduction to Marxism.

The manifesto is mostly just interesting as a historical piece for me, especially in terms of leftist history. Ideologically it's still pretty interesting to read, however some parts of it have naturally become a bit outdated which has even been acknowledged by Marx and Engels some 25 years later.

The edition of the manifesto I read even includes multiple prefaces by Engels throughout the years which further gave an amazing insight into history and what they felt and thought at the time. Additionally the book also included Engel's The Principles of Communism which practically functioned as an FAQ to fully illustrate what exactly Communism is and it stands for.