Here's a great shirt that'll fit anyone, because it's in mens' sizes! It has the newer 2011 jumping Sonic art, with a 'grunge' style blue checkered background. The effect is nice/3D like as the checkers are a brighter blue. This is available in the mens section at WalMart in winter 2011.
This is a little kids' only tee (...you can tell the one in this photo is pretty small) but where can you find it? This is a spring/summer 2012 find. It's all blue, with a blue & white 'screen tone dots' in a circle background for Sonic. It has modern Sonic, quite large so that he's cut off in the corner of the design. He's stepping & pointing, so it's one of the newer (after 2011) stock art pieces. The corner/big art is unusual, which helps the shirt look unique. This is the 'small sizes only' one. There's another that was released later that was larger/teens sizes, thought to be found at Boys section of WalMart
Top Heavy puts the new 2011 stock Sonic 'jumping kick' to use quite nicely on this brown tee. A silver/gray ring with red/black background is all that's needed to make him stand out.
The pose is really dynamic, & this is one of the first shirts to use it. Found at Sears boys/teens section in fall 2011.
This Tee is likely exclusive to Kohl's stores in the USA. It has A nice group of the cast on it, including Eggman, Knuckles, Shadow, Amy Tails Rouge Sonic & Cream. They're under a yellow ring or arch, & the modern logo sits at the bottom. However, look at the bad quality of the design! Is that more of the stupid "Fake Wear" or did this run of shirts just print particularly badly? Fake wear/faux crackle to the ink makes no sense at all on a modern shirt like this. No one would want a rubbed design, so what's going on? Write in if you've seen a better version of this shirt at your Kohl's stores. Inset is the tag (Cloth) that shows it is official. This would be a nice shirt, if not for the design problem.
Here's a fun shirt with Sonic, Tails & Knuckles. They're all in their newer 2011 poses, with corrisponding color background rings. The shirt is blue, with 'grunge look' checkering for the background. You can see the Sonic logo print-tag (not a cloth tag) in the top. This is available at Sears in fall 2011, for their usual price of about 8.00 in the boys/teens area.