Years ago, my go to cap was usually the on-field cap. However, after they changed the material from wool to the current synthetic material, it seems as though the New Era field caps don't fit as well. The 5150 caps sold in mall stores, New Era cap corner, etc. all seem to be more fashion-based with the high crown, etc. The older wool models, although they shrunk over time, seemed to fit my head better. I remember the original black cap in 1990. That was probably my all-time favorite and got years of use. Before that, the "C" cap and then before that the all Navy blue SOX cap from the Veck era. I never really warmed up to the Montreal Expos inspired red/white/blue caps.
Due to the changes in the 5150 caps, I now lean toward the batting practice caps as my go to caps. I like the way the stretch material fits my head and they have lower crowns.