These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Awesome Music: In the original film - "Opening," "Discovering the Neighborhood" and "Ryce's Theme," also the usage of "Roll Over, Beethoven"
Bizarro Episode: Despite the rather improbable things that Beethoven does throughout the series (particularly in the third film), the films remained a pretty realistic feel throughout. Not so much with Beethoven's Christmas Adventure, which features one of Santa's elves as a central character, a magic bag which can produce an infinite number of toys, and Beethoven talking to people after they eat magic candy which allows them to understand dogs.
Fridge Brilliance: George initially believing Beethoven bit the vet makes sense when you consider Beethoven is a large, male, un-neutered and ill-behaved dog.
Fridge Logic: The sequels establish that George had never bothered to get Beethoven fixed in the first movie, despite the dog's out-of-control behavior costing him tens of thousands of dollars.
In addition, in the second movie, a pre-That '70s Show Danny Masterson appears as Ryce's boyfriend. Ironically, Danny's younger brother, Christopher Masterson, later of Malcolm in the Middle fame, actually originally had a minor role in the film, but his scenes were deleted as the producers felt he looked too similar to Danny. (No one on set knew that they were brothers.)
Also in the first movie, the bad guy's mooks are Oliver Platt and the oscar-nominated Stanley Tucci.
Nightmare Fuel: The first movie has a brief shot, complete with ominous music, of what looks like a crematorium. The second movie may have some of this for kids, as one scene has Regina's Mook, Floyd, holding a puppy over a waterfall. He never drops it, though.
Another from the first film Dr. Varnack going through all the lengths to get Beethoven for the sole purpose of shooting him to test a new type of ammunition.
Sequelitis: The first film was a modest hit when it came out, but wasn't anything particularly special. However, the success of the film apparently was enough to give Hollywood an excuse to turn it into a franchise, resulting in a film series that became more and more out of touch with the original with every installment. While Beethoven's 2nd stayed true to the original formula with its then-familiar cast and Beethoven still at his usual canine antics, Beethoven's 3rd saw Beethoven transferred to a new family headed by father Judge Reinhold replacing Charles Grodin, with increasingly uninspired villains and stories appearing in each installment. By the time of Beethoven's sixth film appearance, the series was rebooted and retooled and then the seventh installment, Beethoven's Christmas Adventure had Beethoven talking, finally doing away with what little resemblance the sequels still bore to the original. There was also a short-lived animated series. This hound knows no bounds.
Unacceptable Targets: The American Veterinary Association wrote a letter to the head of the MPAA (Jack Valenti) about the main villain of the first film being a veterinarian.