Check out this cool plush!
This is the "Posable Sonic Plush" by Sega Toys. As you can see here, he's actually standing and 'walking' without any support! It is jointed inside to allow you to pose him however you want, and he'll stay that way. As you can see he does suffer a bit from 'giant mega finger', but that's pretty much the only thing. The head, foot and body shape are all good, as well as the eyes and expression. This is some time post-SA1 (green eyes), and looks quite good! Being able to really stand and pose a plush adds to the fun and display ability, especially because it is well designed.