I prefer Placidus. The wikipedia article is TERRIBLY unclear as to how the MC works in the Equal or Whole House Systems, with this bizarre statement, in bold, that somehow attempts to clear it up. That statement does not do it for me. No one as of yet has been able to explain it to me. Ah well.
Interestingly, Placidus was popularized as a reaction to the current trend of heliocentrism going on during the Scientific Revolution in Europe, by none other than the Catholic Church. (So even those who believe astrology is a work of the devil and goes against Christ can still use Placidus, nice.)
Placidus is the most recent form of house systems. Hellenistic Astrology, beginning in the 1st and 2nd centuries BCE, used Whole House. Equal House became popularized later on, and Placidus, as I said, is the most recent and modern of the house systems. There are issues with it, namely the issues with house size as the latitude increases or decreases significantly from the equator.
I like that Placidus is geocentric. While our solar system is obviously not (right guys, right? we orbit the sun I think...), we are BORN on the earth, not the Sun. Our center, our grounding, is in the Earth. So our experience of the stars if from our place on the Earth. We are reaching for the Sun, the Moon, etc.
At least, those are my thoughts.
mod.