Here are 2 interesting figures.
This Sonic & Chao are likely part of a larger set. If these look familiar, they should. They're VERY similar to some Japanese keychains. They're fully 3D figurals, on little bases, each with a name-plate. Dare to compare? See Japan Keychains 1, but look all over the page and you'll even see a very similar classical one. These aren't common, but fun to collect and display. 

Here's a good turn around for the Tails. He has good detail, & a sturdy pose. A bit bigger than one might expect, he has pegs on his feet that allow him to be taken off the base. The texture on the back of his head is where he's stamped for copyrights & Sega. Photo & owned by: Ultimate Tails

(TODO: Fix link when Japan Keychains is added)