I have made a few (crappy) ones that are on Aminet (see link in my signiture).
In the right hands AMOS can be used to make some great games. Right now I'm working on a demo (in assembler) and then will probably go on to make a port of a Spectrum game I made - but in all likelyhood I'll probably code it in assembler as it gives me full control over the Amiga with maximum speed possible.
Getting the maximum speed in AMOS can be tricky, but I still use AMOS to code tools I use (e.g. bitmap (16 colours or less) to IFF conversion).