Escaping the claustophobic Enterprise sets, most of this comedic episode was shot outdoors on location (at Africa, a ranch, and the nearby Vasquez Rocks, both just north of Los Angeles), and the feeling of freedom it gives combined with a fresh musical score makes "Shore Leave" a fan favorite.
In truth, it's a somewhat bizarre offering. With Grace Lee Whitney gone from the series, Yeoman Rand is replaced by Yeoman Barrows, which forces the writers to switch some of the planned Rand/Kirk scenes to Barrows/McCoy. Meanwhile, Barbara Baldavin, who plays the bride to be in "Balance of Terror", returns after successfully auditioning for another character. For the sake of continuity, they try to use her character's name from the previous episode (Angela) but don't always get it right. Eventually she runs into a tree and disappears from the episode anyway, though she does return as another character in "Turnabout Intruder". (I suppose it helps to be married to the casting director). Meanwhile, Kirk gets into one of the longest fight sequences in television history, a multi part scuffle that weaves its way through the episode and which is played off as "boys will be boys" and "isn't this is great time?". Along the way, he also runs into an old fling, scored with an infamous "love theme" that includes a painfully out of tune cello. (I seriously can't understand how this bit of music made it onto television. I mean, even if it's the best the cello player can do and no one else is available, why wouldn't they simply get rid of the cello part? Or was the music director tone deaf and unable to hear it? The cello player was certainly tone deaf; that goes without saying). Curiously, the sound editor also uses a wind chime effect for the planet surface that's thankfully never used again.
As the story, such as it is, meanders along, it becomes increasingly clear that the writers don't really have a plan and are just making it up as they go along, although it's also clear the cast is having a ball. In truth, Roddenberry himself wrote much of the script (supposedly under a tree) at Africa, . while the cast and crew were already shooting (and ad libbing). It all adds up to a unique, memorable episode but one that lacks the greater meaning of some of the others. In the end, it's really just a malfunctioning holodeck episode before holodecks.
The animated series includes a sequel to this episode called "Once Upon a Planet".
The Remastered Version: It's just the basic redo here, with a new ship and planet; though it's a notable upgrade to the original, which has a green blob for the planet (which is actually the "Earth" from Miri painted green) and a flipped shot of the Enterprise that causes the letters on it to be reversed. The new effects include a planet that matches the look in the animated series, a nice bit of retroactive continuity.