One of these or a mix of - history, archaeology, and literature. But as they say, you never know.

I absolutely knew even when I left school ("school" school) that none of these would pay, so I assume your question has an implicit "if money was no concern". Because money/job was the reason I picked engineering and CS in college. While I did quite well (academically and professionally), I never loved it. Maybe I liked it here and there. Then I knew this would happen; that's the reason I was at least prudent enough to never do that CS MS (with multiple options for full scholarships in Europe around a decade ago). But not prudent enough to explore masters in many of the non-STEM fields that were there for the taking pretty much. Some of those might have paired well with this STEM bachelors in some way or the other.