TOS: Grand fun, big ideas. A stumble at the finish line saved by some great movies.
TNG: Rocky start, brilliant middle, shaky end. Movies that weren't as good as the series.
DS9: Gently TNG at the beginning, later finding it's own beautiful voice.
VOY: So much potential. Some wasted, some not.
ENT: Poorly timed, rarely really great but also unfairly overlooked.
ALT: A rollicking, rickety embrace of the more obvious TOS elements.