The short answer is that the beneficiaries of the crisis were the people who created the securities (such as CDO's) that were subsequently determined to have a significantly lower value than the original sales price. They made profits by assembling a set of (say) mortgages and securitizing them, selling those securities for more than the cost of the mortgages. Behind those people is a host of others who profited by developing properties, financing that development, manufacturing housing materials, originating mortgages, and so on. Most of these people are blameless, but they profited nevertheless. Others knowingly created and sold assets knowing that these assets had hidden flaws.

The longer answer (as though the preceding were not long enough) is that there doesn't have to be a winner for every loser nor a loser for every winner. If you reorganize or combine a set of assets in a way that benefits others (or invent something or find a better way to do something), you will make a profit but there is no loser. If you destroy something of value in a fit of rage, there is no winner.

The people who "lost money" didn't actually lose *money*. Instead, the collections of assets that they held fell in value and, as a result, the amount of money that those assets could be converted into became less. The amount of money in the economy did not change as a result of the crisis (except for the changes deliberately made by the central bank (Federal Reserve)).

Sorry to be so long-winded. And please don't read this to mean that I don't think there are any villains in this crisis - there certainly are. And, as usual, some of the innocent will be convicted and some of the guilty will either get off scot free or be knighted!