Common Lisp was designed by a committee, and is widely regarded as an excellent language (or at least an excellent Lisp). It even has principles that it sticks

Common Lisp was designed by a committee, and is widely regarded as an excellent language (or at least an excellent Lisp). It even has principles that it sticks to throughout. For example, it is deliberately designed to be a multi–paradigm language, allowing the user to write programs in functional, imperative, or object–oriented styles without forcing one or the other.