There are many awesome ones. Last I wowed was Knuckles one in CEZ2.
I´m having a really tough time trying to find Tails emblems in DSZ2 and RVZ1. I´ve flight on every room, I´ve go everywhere underwater (and underlava, even dying behind it with the green shield)... Yet there´s somewhere in both levels I haven´t been and I can´t see it...
Any clue? (Without spoiling the exact location, just a hint, like "it´s really high near some lava" or "in a secret path"...)
I loved Sonic's DSZ (2?) emblem.
[spoiler:8b5381cb5f]You have to get to the spot where you see a dragon on the floor. Step on the eye to open a door. Go in. Put 2 Gargoyels on a srping underwater. Then push it in the crusher so you can walk. Do the same with the next one. And there is the emblem for Sonic.[/spoiler:8b5381cb5f]