Beginning in 1998, Sonic began a retrofit program, called " Sonic 2000 ", to redesign and update all stores in its chain to what was called a " retro-future " look.

* Sonic Archives # 0 ( February 2009 ) ( An Archives rebranding of Sonic: The Beginning )

Also during this phase, United Game Artists ( formerly Sega AM9 ) merged with Sonic Team Japan in 2003 to start the Sonic Riders series.

Their next project was Sonic Heroes, released in 2003.

They released three games for the Sega Dreamcast before they were merged with Sonic Team Japan in 2003.

Having never before had any kind of retail chain other than two fuel stations and a small Chevrolet dealership, Celina saw a Sonic restaurant completed in 2003.

2003 saw the three surviving members of MC5 — Kramer, bassist Michael Davis, and drummer Dennis Thompson — performing as the MC5 at the 100 Club in London with Fred " Sonic " Smith's place temporarily being taken by Nicke Andersson of The Hellacopters, vocal chores at that time being filled variously by David Vanian of The Damned, Lemmy of Motörhead, Ian Astbury of The Cult, and singer Kate O ' Brien, as well as seeing Charles Moore and Buzzy Jones reprise their roles in the brass section from the High Time album.

Sonic Youth, joined by percussionist Tim Barnes, played along with silent Stan Brakhage films at a 2003 benefit show for the Anthology Film Archives.

An enhanced port was released in 2003 as Sonic Adventure DX: Director's Cut for the Nintendo GameCube and in 2004 for Microsoft Windows.

It is the first multiplatform title in the Sonic series, developed for Nintendo GameCube, PlayStation 2 and Xbox and released in Japan in December 2003, in North America in January 2004 and in Europe in February 2004, later receiving a release for Windows in November 2004.

29 – ( CD Sampler, Enhanced ) 2003, Track # 2 " Collapsed " – Sonic Seducer

Chao were recurring characters in the Sonic X anime that ran from 2003 to 2006.

Celebrating its 50th birthday in 2003, Sonic briefly added the Birthday Cake Shake to the menu.

The Game Gear version was included as an unlockable game in Sonic Adventure DX, released for the Nintendo Gamecube in 2003 and PC in 2004.

Sonic Foundry () is the former developer of various media software suites, which were purchased by Sony in late 2003 for $ 18 million in cash and the assumption of certain liabilities and obligations.

Sonic Advance was also ported to Nokia's N-Gage system on October 7, 2003, under the title SonicN.

A port of Sonic Advance titled Sonic N was released as a launch title for the Nokia N-Gage in North America on October 7, 2003.

Sonic Advance 2 was released in Japan on December 19, 2002, in North America on March 9, 2003, and in the PAL region on March 28, 2003.

In 2003, Hanley was approached by Jun Senoue from Sega to co-write and perform on an original song for their upcoming entry in the Sonic the Hedgehog series, entitled Sonic Heroes.

* Journey With An Angel ( Echo Sonic, 2003 )

* Sonic Archives # 1 ( November 2006 ) ( A reprint of issues # 1-4 of the regular series )

* Sonic Archives # 2 ( December 2006 ) ( A reprint of issues # 5-8 of the regular series )

* Sonic Archives # 3 ( May 2007 ) ( A reprint of issues # 9-12 of the regular series )

* Sonic Archives # 4 ( June 2007 ) ( A reprint of issues # 13-16 of the regular series )

* Sonic Archives # 5 ( September 2007 ) ( A reprint of issues # 17-20 of the regular series )

* Sonic Archives # 6 ( October 2007 ) ( A reprint of issues # 21-24 of the regular series )

* Sonic Archives # 7 ( June 2008 ) ( A reprint of issues # 25-28 of the regular series )

* Sonic Archives # 8 ( August 2008 ) ( A reprint of issues # 29-32 of the regular series )

* Sonic Archives # 9 ( October 2008 ) ( A reprint of issues # 33-36 of the regular series )

* Sonic Archives # 10 ( March 2009 ) ( A reprint of issues # 37-40 of the regular series )

* Sonic Archives # 11 ( August 2009 ) ( A reprint of issues # 41-44 of the regular series )

* Sonic Archives # 12 ( January 2010 ) ( A reprint of issues # 45-48 of the regular series )

* Sonic Archives # 13 ( August 2010 ) ( A reprint of issue # 49 of the regular series and the Sonic # 50: Director's Cut Super Special )

* Sonic Archives # 14 ( December 2010 ) ( A reprint of issues # 51-54 of the regular series )

* Sonic Archives # 15 ( June 2011 ) ( A reprint of issues # 55-58 of the regular series )

* Sonic Archives # 16 ( November 2011 ) ( A reprint of issues # 59-62 of the regular series )

* Sonic Archives # 17 ( February 2012 ) ( A reprint of issues # 63-66 of the regular series )

* Sonic Archives # 18 ( July 2012 ) ( A reprint of issues # 67-70 of the regular series )

* Sonic Archives # 19 ( December 2012 ) ( A reprint of issues # 71-74 of the regular series )

* Sonic Archives # 20 ( March 2013 ) ( A reprint of issues # 75-78 of the regular series )

* Sonic Select # 1 ( April 2008 ) ( A reprint of the 48 page specials, " Sonic In Your Face ", " Sonic & Knuckles ", " Sonic Triple Trouble ", and one story, " The Substitute Freedom Fighters " from " Sonic Live ")