Aspiring film critic, I love diving into films and dissecting why I feel they are enjoyable or barely bearable.
If I were to choose between "The Hobbit" or "The Lord of the Rings" trilogies, I would definitely pick "The Lord of the Rings" trilogy. These movies are just all around better. The Hobbit movies are respectable, but Lord of the Rings is great. Among the reasons why I would choose Lord of the Rings over The Hobbit includes; characters, length and pace, and emotion.
The characters in the Lord of the Rings are more memorable than the Hobbit. Granted there are characters from both series in the mix, but when I ask you about Legolas, you would be more prone to remembering him in Lord of the Rings rather than The Hobbit. He was a more memorable character than he is in The Hobbit trilogy. After watching The Lord of the Rings, I was able to remember the characters names and their personalities. While watching those films I understood why the characters acted the way they did. The Hobbit trilogy doesn't do this as well. Granted, some of the characters are developed very well. However, there are really only 3 or so dwarves in the main group that an audience member can really feel attached to. Both of these trilogies have good characters, but the Lord of the Rings takes these good characters and makes them great.
Secondly, both of these trilogies include three long films. The Hobbit is a single book, whereas each film in the Lord of the Rings trilogies is a single book, case in point? The Hobbit suffers from slow pacing. Some parts seem to drag on for too long. The Lord of the Rings trilogy cuts out the fluff and leaves us with the "need to know" details in each film. This creates a faster paced and exciting film trilogy. The Hobbit could have been easily cut down to a very long single film, or two decent length films. Had they condensed the material to a couple of two and a half hour films, they could still have good character development, and keep the plot moving at a faster clip. Overall, the Lord of the Rings films do not feel like they are each three hours long, while The Hobbit films feel slightly longer than their runtime would dictate.
Lastly, The Lord of the Rings films are more emotional than the Hobbit. As an audience, we can feel the characters' pain and anguish. We feel their happiness when they succeed. In the Hobbit, we feel relieved that the journey is over, but more or less because it took so long to accomplish. There are moments in the Hobbit that are emotional and they are genuine and can reel the audience in. However, the Lord of the Rings does it better. The emotion we feel in these films is affected by the previous elements mentioned, characters and pace. Without these elements being as strong as they are, being emotionally invested becomes easy. The score to the Lord of the Rings does an amazing job of relaying emotions as well. This is another area where the Hobbit lags behind. Although there is epic music in both, the tunes to the Lord of the Rings are what a person is more likely to start whistling when going on life's quest.
All in all, both trilogies are enjoyable. If you are looking to watch three films that are okay and won't have too much of an impact on your love of film, watch the Hobbit films. If you want to watch one of the most successful and riveting trilogies of all time, watch the Lord of the Rings trilogy. It has better character arcs and growth, pace, and emotion than the Hobbit.