"No one here is really interested in the commons..."
I must respectfully disagree with this and the sentiment that *only* the prefs should be discussed here.
Personally the bulk of my holdings are preferreds, but I bought over 10k commons between .20-.40 as a highly speculative (and cheap!) investment.
I do agree with everything else Jared said- the prefs are more highly valued by virtue of their place in the capital structure of the company. The only ways they can be dealt a losing hand are thru receivership or if 2/3 of the holders vote it so (unlikely!). It could be that the payoff potential of the commons is higher, but in terms of 'safety'.... Preferred.