I think most of us here are Marxist-Leninists. The reason for me at least is fairly simple: it's the most scientific (in the sense that it looks at the world through a materialist lens and analyses it rationally, systematically and holistically) and it demonstrably works when used to guide revolutionary practice.
The second part is particularly important because if your ideology doesn't work in the real world then what good is it? I'm paraphrasing here, but: "The point isn't just to analyze the world, it's to change it." Only Marxism-Leninism has managed to produce successful revolutions that create stable socialist societies which have improved the level of human well-being beyond what any capitalist system would be capable of doing in the same circumstances.
Marxism-Leninism is also flexible enough to adapt to changing circumstances and to incorporate a newer and better understanding of how the world works. Dogmatism is the death of science. I find that China has some great phrases that express the scientific approach to socialism, such as: "Crossing the river by feeling the stones" and "Seeking truth from facts". We observe the world as it is to form theories, proceed forward through trial and error, adopt what works and discard what doesn't.
This also means we should be open to learning from many different sources, so we should not attach ourselves to one particular person or country (though obviously some have been objectively more successful than others, and we should study why that is and learn how we can replicate their successes and avoid their mistakes).