Liberal Arts
I was lucky to attend a small, private liberal arts college. Took me 15 years to pay off the loans, but they were not huge, and I had deferments while in grad school.
While liberal arts are under attack as being worthless, including on this forum in the past, I am a huge advocate. I learned how to learn. I was exposed to music theory. I had enough credits to be an English major. And, as you say, critical thinking developed not only in the classroom, but through discussion and debate with my peers. It was worth every damn dollar.