This is a simple list of Grand Theft Auto games, in order of release date, grouped by era.
Grand Theft Auto I era (1997 - 1999)
Grand Theft Auto II era (1999 - 2001)
Grand Theft Auto III era (2001 - 2007)
The GTA III Era brought a 3D perspective to the game and firmly established the humour and features of the series. This era is considered to be closed-off and finished.
Grand Theft Auto IV era (2008 - 2011)
The GTA IV Era only firmly consists of GTA IV, and does not overlap with previous eras. However, there are many references to previous games, including several businesses and brands (eg Sprunk) and other hidden references.
Grand Theft Auto V era (2012 - ????)
The GTA V Era is the next era in the series. Unlike the previous era, GTA V Era will somehow overlap with the GTA IV Era. There are several minor characters to reappear. However, no main characters will be reoccurring. These two eras are supposed to merge into one, HD Era, or HD Universe. Therefore, all the characters featured in GTA IV Era actually exist in this universe, nevertheless, many of them will not be featured in any future games.