Ranger - Named after Lone Ranger commercial that I saw right before leaving for PetSmart.
Marius - Suggested by a member here to match Eponine
Eponine - Named after character from Les Mis. She is feisty like Eponine so that's how she got her name.
Neptune - I like Roman and Greek mythology, so i went with one that made sense
Gerard - Named after Gerard Butler, I went from seeing Phantom of the Opera (my other favorite musical next to Les Mis.. although I prefer the stage version of both) to PetCo because the movie theater was close, saw him and took him home. This was in 2004 or 2005.
Bob - Named by a co-worker who said all fish need to be named Bob. This was 2004 as well.
Cow - I wanted oddest name I could think of. This was 2002-2003.
So, it looks like I mostly turn to popular culture and/or other people.