MarineAquarium has really nice saltwater fish, excellent quality imaging:
(Somebody needs to build him a new website, you'd never know how nice the program is looking at the site .) One word of warning though, historically it hasn't been updated very often - say every few or several years. It's best if you ignore what he says he's going to do and just consider it to be "as is" to avoid frustration. It has a handicapped free trial download. Nice fishtank.