Teacher recommendations

I’m applying to a college that requires 2 recommendation letters, one from your guidance counselor and the other from another teacher. I think I am going to major in Computer Science and I’m not sure who to ask to do my teacher rec. I could ask my ap chem teacher bc I think she knows me the best and she has seen me struggle but improve the most by the end of the year or my calculus teacher bc last year she wrote me a really good one for a summer program or my comp sci teacher bc that is the field I’m going into. However, last year when I asked her to write me a rec for the same summer program, hers was just really generic. My question is who do you guys think I should ask for my teacher rec? And do colleges care about the credibility of the teacher more or my actual personality in the letter?

Chem or Calc, I’d say. Clc has already proven s/he can write a good one…the comp sci teacher doesn’t seem like a good one to ask based on the one s/he wrote before.