What do Lelouch and Light have in common?

Both are genius-level strategists who use supernatural power to pursue world transformation, both work toward something framed as justice, both lie constantly to maintain their cover, and both die as a result of their plans. Both are anti-heroes in the technical sense — protagonists we follow while questioning their methods.

How do their goals differ?

Light wants to create a world without crime by becoming its god and judge — eliminating criminals unilaterally. His goal is control. He doesn't want to end suffering; he wants to be the arbiter of who suffers.

Lelouch wants to create a world where his sister Nunnally can live in peace — and expands this into a vision of a world without war. His goal is transformation. He builds coalitions, delegates, and eventually designs a system that survives his death.

Who is more genuinely self-aware?

Lelouch. Light has enormous blind spots about his own corruption — he tells himself he's saving the world while enjoying the power increasingly. Lelouch is consistently aware that he's becoming a monster, acknowledges it, and continues because he's calculated that the outcome justifies it. The self-awareness doesn't redeem him; it makes him more tragic.

Whose plan is more sophisticated?

Lelouch's. The Zero Requiem is a multi-year plan that accounts for his own death and builds peace through his sacrifice. Light's plan is essentially "keep killing until I'm the only judge left," which collapses as soon as he faces a genuinely equal opponent (Near).

Which anti-hero makes the more compelling argument?

Depends on what you're testing. Light tests the corruption of absolute power. Lelouch tests what genuine sacrifice looks like when pursued to its logical end. Both arguments are worth making; both characters make them with full commitment.