Marxist-Leninism and the lesser known works of Stalin and Lenin

[Kingfish]

Stalin and Lenin especially were prolific writers and occupy rather prominent roles in the authoritarian left history and thought. How valuable are the other works by them outside of the main ones like:

Imperialism, the Highest Stage of Capitalism
The State and Revolution
What Is to Be Done?
"Left-Wing" Communism: An Infantile Disorder
April Theses

And for Stalin: Marxism and the National Question

Are there any particular letters or volume(s) of Lenin or Stalin’s completed works that deserve special attention? Whilst I am starting to get into the groove of reading political works the thought of having to sift through thousands of pages is still rather daunting.

[Comrade #138672]

There is a short speech by Lenin on anti-Jewish pogroms, which deserves attention in my opinion. It is a must read for everyone, no matter your politics (unless you are a fascist).

[jookyle]

Works of Lenin to add to the list you've already given(including the anti-jewish porgrom speech) :
http://www.marxists.org/archive/lenin/works/1919/oct/30.htm
http://www.marxists.org/archive/lenin/works/1921/jan/25.htm
http://www.marxists.org/archive/lenin/works/1914/self-det/index.htm
https://www.marxists.org/archive/lenin/works/1919/mar/x10.htm


Works by Stalin that are, in my opinion, worth reading:
http://www.marxists.org/reference/archive/stalin/works/1906/12/x01.htm
http://www.marxists.org/reference/archive/stalin/works/1924/foundations-leninism/index.htm
http://www.marxists.org/reference/archive/stalin/works/1924/11_19.htm
http://www.marxists.org/reference/archive/stalin/works/1926/01/25.htm
http://www.marxists.org/reference/archive/stalin/works/1936/03/01.htm
http://www.marxists.org/reference/archive/stalin/works/1951/economic-problems/index.htm

[consuming negativity]

This is not entirely and completely relevant to your post, OP, but one thing I noticed whenever I've tried to delve deeper into the specific tendencies are that the threads stickied in these forums are woefully inadequate and incomplete. Not due to not being good, but because most of the links are broken. The results of what people post here may be worth sticking somewhere in those overview threads.