Fifth Sun has made this washed out looking tee. The design is purposefully light, on the mottled blue background. It's simple, with the classic style logo around Sonic's winking face on a yellow circle. Where is this sold? Write in if you know.

Photo by Sonicrush05

This red classic style Sonic shirt is likely a JC Penny Store exclusive. The graphic & name are nicely shaded, so this is a good bit of art if you don't already have something similar.

This can be found in summer/fall 2011 in stores. You may be able to buy at JCPenny.com for about $9 if link still works. Info by Sonicrush05. 

Here is a curious shirt that won't say who has produced/ licensed it. The tag & back stamp just say 'SEGA'. (Note paper tag with Sonic & Tails) The graphic here is nice and large, going full bleed to the edges of the shirt. It's classic stock art 'winking Sonic' again, but they've tilted the face. See how it fades at his ears & edges? Those are actually screen-tone dots, to give the impression of fading, without resorting to damaging the design. This is available at Sears in summer 2011, for about 8.99 (or 14, if not on sale)