My compilers course used Java to implement a simplified Java-like language. Writing a compiler in Java isn't as gloriously straightforward as in Lisp/ML/Haskell, but it's a lot less annoying than C.

Lisp derived languages are quite easy to implement, e.g. "An Incremental Approach to Compiler Construction" paper.

Wirth has published compiler books based on Pascal and Oberon, quite simple single pass implementations.

The language proposed by the Tiger book variants (a ML like language) is also quite simple to implement.

> Which language is easy enough to compile, and pleasant enough to write a compiler in?

Why write a self-hosting compiler? Use Haskell to write a C compiler, if you must.

(If you want the identity there, use a Scheme to write a Scheme compiler.)