Anything? I've used 57s, 58s, 91s, 609s, 421s, 121s, I5s, Cheap $50 condensers, CX112s, omnis, just about anything and have gotten a good sound.
I bet if I put a regular 57 and a transformerless 57 against the same amp in the same mix, your buddy hotapples couldn't tell the difference. Use...