Dynasty Warriors 5

Unlockables:

Liu Bei: Finish the game as Guan Yu and Zhang Fei.
or Finish Musou mode with four Shu characters.

Meng Huo: Defeat Meng Huo each time that he appears during the Nanman
Campaign or Finish the game with Zhuge Liang and Lu Xun in Musou mode.

Sun Jian: Finish the game as Sun Ce, Sun Quan, and Sun Shang Xiang.
or Finish the game as Zhou Tai to unlock Sun Jian quickly.

Xiahou Yuan: Finish the game with Xiahou Dun and Zhang Liao.
or play half the character's Musou mode.

Cao Cao: Finish the game with any four Wei officers.
Cao Ren: Finish the game as Cao Pi.
Da Qiao: Finish the game as Sun Ce.
Diao Chan: Finish the game as Lu Bu.
Dong Zhuo: Finish the game as Diao Chan.
Gan Ning: Finish the game as Ling Tong.
Guan Ping: Finish the game as Guan Yu.
Huang Gai: Finish the game as any three Wu officers.
Jiang Wei: Finish any three Shu Story modes.
Lu Bu: Finish the game with one officer from Shu, Wu and Wei.
Lu Meng: Finish the game as Gan Ning.
Pang De: Finish the game as Ma Chao.
Pang Tong: Finish the game with any three Shu officers.
Sima Yi: Finish the game as any Wei officer.
Sun Ce: Finish the game as Sun Quan.
Xiao Qiao: Finish the game as Zhou Yu.
Xu Huang: Finish the game as any three Wei officers.
Yuan Shao: Finish Cao Cao's Musou mode.
Yue Ying: Finish the game as Zhuge Liang.
Zhang He: Finish the game as any two Wei officers.
Zhang Jiao: Finish Liu Bei's, Sun Jian's, and Cao Cao's Musou modes.
Zhou Tai: Finish the game as any Wu officer.
Zhu Rong: Finish the game as Meng Huo.
Zhuge Liang: Finish the game as any Shu officer.
Wei Yan: Finish the game as Huang Zhong.
Shura/Expert mode: Finish one Musou mode as the Wei, Shu, Wu and Other forces.
Opening sequence: Finish one Musou mode as the Wei, Shu, Wu and Other forces.
Zuo Ci:Unlock every other character. Not neccesarry to play with them.
Credits: Finish Musou mode.

Chaos mode: Finish Musou mode as Lu Bu.
or Finish Musou mode as a character from the Wei, Wu, and Shu forces.

Kessen 3 and Samurai Warriors: XL trailers:
Finish Musou mode in hard mode.