What are all the Sonic games in storyline order?

Answer 1

Classic Era:

Sonic the Hedgehog (1991)

Sonic the Hedgehog 2 (1992)

Sonic the Hedgehog 3 and Knuckles (1994)

[Sonic CD (1993) is considered to be a canon game, however it's speculated as to whether it's before or after Sonic the Hedgehog 2 due to the lack of Tails, yet being produced at the same time as Sonic the Hedgehog 2.]

Sonic the Hedgehog 4 (2010) [Although technically a modern game, it's set to take place after Sonic 3 and Knuckles, making it placed here storyline wise.]

There are also numerous other 2D releases, however the time in which they take place isn't established, but some listed in order of release date, so presumably in the Sonic universe's chronoglogical order are:

SEGASONIC the Hedgehog (1993)

Sonic Chaos (1993)

Sonic the Hedgehog Triple Trouble (1994)

Sonic 3D Blast/Sonic 3d: Flickies' Island (1996)

Sonic Blast (1996)

Modern Era:

Sonic Adventure (1998)

Sonic Adventure 2 (2001)

Sonic Advance (2001)

Sonic Advance 2 (2002)

Sonic Heroes (2003)

Shadow the Hedgehog (2005)

Sonic Battle (2003) [Takes place after Shadow the Hedgehog, due to Shadow having his memory, and Rouge's acknowledgement of Omega.]

Sonic Advance 3 (2004) [Takes place after Battle due to Gemerl's existence.]

Sonic Rush (2005) [Speculative as to where this game belongs. Either before, or after Sonic the Hedgehog 2006.]

Sonic Rush Adventure (2007)

Sonic the Hedgehog (2006)

Sonic Rivals (2006)

Sonic Rivals 2 (2007)

Sonic Unleashed (2008)

Sonic and the Secret Rings (2007)

Sonic and the Black Knight (2008)

Sonic Colours (2010)

Sonic Generations (2011)

Sonic: Lost World (2013)

The remainder of the games are generally spin-offs that could fit just about anywhere in the series.