This batch of Slayers OVA episodes is better than the movies simply because it doesn't try to stretch an episode's worth of story into a feature length movie.
In episode 1 Lina and Naga try to rescue some villagers from some ruins ruled by the Vampire Steindorf, only to find out that they've been tricked. Luckily Steindorf doesn't pose much of a threat, especially in his true form. Naga seems to cause Lina more headaches though. What's nice is that in a flashback we also get to see the first encounter between Lina and Naga.
Episode 2 is the best of the bunch where the rich Fitzmeier hires Lina to protect his daughter Sirene. Sounds easy enough, but unfortunately Sirene annoys Lina with her narcissist behavior and her similarities to Naga. When Lina accidentally gets Sirene kidnapped by the wrong group of bandits, she has to rescue her with the help of Naga. Much to Lina's surprise Naga seems to have quite the unusual and hilarious effect for some people.
Episode 3 seems too familiar with Lina and Naga choosing opposite sides in a conflict between fashion designers Tatjana Hayward and Marty Lenford. They also end up fighting in giant golems. Slayers Great anyone? At least it's only 25 minutes long this time.