I think the ones which can self-compile are most interesting, because it passes a "it's not just a trivial example anymore" point. To do that in a single relatively small file also makes it convenient for studying.

Mini-C is even more amazing if you look at its description:

I set myself a challenge: write a self-hosting C compiler in 10 hours.

Although the language it accepts, being untyped, is closer to B.

Also nice to see my personal favourite, C4, in the list.