Lately I've been playing through quite a few custom Co-op Campaigns with some friends, and we've come upon numerous really good ones. The ones we regularly play are listed below, are there any customs of really good quality that we've missed out on?  We play on Campaign mode, so we're not interested in Survival maps or maps focused on Versus (unless they are fun in Campaign also).  Death Aboard: http://www.l4dmaps.com/details.php?file=33 Heaven ...