I never really got into the other spin-offs, like "Voyager" and "Deep Space Nine." I might have to give them a try sometime, but at first glance, they aren't really interesting to me. Maybe they'll grow on me if I watch an episode or three.
I wasn't a big fan of "Voyager" because I couldn't get into Captain Janeway. The "Deep Space Nine" series was good though, and became one of my favorite shows. There's lots of action and interesting characters. Odo, Worf, and Quark made the show worth watching if nothing else.