Which of these UCs is the best choice for computer science?

I was accepted for computer science at UC Merced, UCR and UC Santa Cruz.
Which would be the best choice for CS and also for college life in general.
I don’t seem to hear alot or see a lot written about UC Santa Cruz. How does it compare to the other UCs overall?

Have you visited all the schools? I would say UCR/UCSC would be your best choices for CS but for college life in general, both have a very different in vibe. You really need to visit to get the best perspective.

I have not visited any of these schools and have only read about them. In terms of college life, extracurriculars like the ability to join a band etc., vibe etc. which one would be a better fit?

That depends on you. What are you looking for as far as campus life and vibe go?

No one knows how you will like the schools. You have to visit since you will be living there for 4 years.

All 3 of my kids, visited EVERY one of their admitted schools. They were admitted to your listed schools:
None of them liked the location of Merced.
One found UCSC tolerable, but didn’t like the cold weather, another child didn’t like the vibe.
All 3 liked some aspects of Riverside, and they all agreed to something about it.
None of my kids attended those schools.

No one can tell you how YOU will feel at these campuses. You have to visit.

CS is very strong at UCSC and would be a very good first choice If you like the campus,

UCSC > UCR > UCM, both for CS and overall academics/selectivity.