Currently you have a choice CLISP, ECL and SBCL Common Lisp implementations packaged for NetBSD.
UtiLisp32 is also available in the NetBSD package collection
Other Common Lisp implementations work on NetBSD as well, even if they aren't packaged separately for it: see CMUCL.
Could someone PLEASE update and/or maintain the sbcl package in NetBSD's pkgsrc? Yes, we're working on it, see below.
Could anyone PLEASE fix bootstrapping SBCL with CLISP or make it work with ECL?