The only other game to score that highly is Legend of Zelda: Ocarina of Time. Also notching up a score of 99 out of 100, the Zelda game was released in 1998 on the Nintendo 64 platform.
Previous high achievers include Soul Calibur (Dreamcast) and Tony Hawk's Pro Skater 2 (PlayStation), both with 98 out of 100.
Halo (Xbox) and Metroid Prime (GameCube) are two of the few games to reach 97 out of 100. GTA III from 2001 also scored 97 and Wii Super Mario Galaxy is the most recent highly praised game of recent years with a metascore of 97.
Metacritic takes an average score from the reviews it compiles. GTA IV, released today, has had its review score based on 23 critics reviews so far.