8. Halo 2
Halo 2, released in 2004, had a significant production cost of approximately $150 million. As a direct sequel to the original, it built upon the groundbreaking success of its predecessor and pushed the limits of the gaming hardware at the time.
The title introduced a gripping single-player campaign, new multiplayer modes, and advanced graphics. The combination of stunning visuals, a compelling story, and a huge online component made it one of the most successful and expensive titles of its generation.