I assume you mean beneficial to humans?
Viruses make up a large portion of Earth’s ecosystem, and a large class of them help keep bacteria in check.
https://en.wikipedia.org/wiki/Bacteriophage
There are even efforts to try and harness them to treat bacterial infections.
Additionally, a good chunk of our DNA is from ancient viruses, so homosapiens wouldn’t be what we are today without viruses.
Viruses affect other things too, including bacteria! Bacteriophages are the first to come to mind
https://m.youtube.com/watch?v=SbvAaDN1bpE
Sorry to link to a video, but this recent Kurzgesagt video covered your question pretty closely :)
https://www.youtube.com/watch?v=YI3tsmFsrOg
There are beneficial bacteriophages for humans and other animals and plants.
There is the “Luck Virus” and “Sexual Magnetism Virus” poor Rimmer
This has made Mr Flibbles very cross!
I had hoped a few would get this
There are viruses that make some plants look more appealing to some people. For example they are the cause of these striped patterns on tulip petals.
Probably, yeah. Their whole schtick is to move DNA around and fuck up genomes n shit. They’re evolutionary drivers.