About the best thing that can be said about the first Trek movie was the soundtrack was memorable (Ilia's Theme and the Klingon theme being noteworthy) and the special effects were a leap forward from the series. However, the movie itself was at least 20 minutes too long with far too much time spent admiring the Enterprise in space dock. The Starfleet uniforms were sorely out of place. But we get to see the original crew of Enterprise reunited for later (and better)adventures.
As any sci-fi fan will tell you, the series Firefly was critically acclaimed but cancelled by the short-sighted execs at Fox. The browncoats (as Firefly fans are known) clamored for a movie to resolve some of the plot threads from the series. This movie captures the spirit of the series with the characters' crisp dialouge and an entertaining plot. Even the non-initiated will enjoy this movie, however one will wonder what might have been if the series had continued.
This entry featuring the original crew of the USS Enterprise was lighthearted fare compared to Wrath of Khan and The Search for Spock. What this movie lacked in action, it made than made up for in heart and its environmental message. And who can forget the funny moments as Kirk and co. wander the streets of 20th century San Francisco?
I remember watching "Best of Both Worlds" during the original run of Star Trek: TNG. Here, the picture is crisp and the visual and sound effects have been enhanced. A definite "must buy" for any Trek fan.