Conversation so far:
How many records has Linkin Park sold?
Linkin Park has sold 70 million records worldwide.
What was Linkin Park's best selling album?
Linkin Park's best selling album is Hybrid Theory.
When was Linkin Park's Hybrid theory released?
Hybrid Theory was released on October 24, 2000

Question: what was Linkin Park's greatest achievement?
Self-contained rewrite: what was Linkin Park's greatest achievement?