The following information was collected by Paul Overberg after he analyzed the 2001 financial disclosure statements by members of Congress. It was published in, of all places, USA Today. This information only refers to stocks. Mutual fund investments, trust funds, and the like are not detailed in the disclosure statements and so that information is not publically available.

Stocks most widely held by Congress:
General Electric
Intel
Pfizer
Cisco
Merck
Lucent
ExxonMobil
AOL Time Warner
Citigroup
Johnson & Johnson

It is not a violation of Congressional ethics to benefit from one's own actions as a representative so long as those same benefits are (theoretically) available to the general public.

Over 20 members of Congress reported capital gains income (that's income earned from investments) in excess of $100,000. Five of those representatives reported capital gains income in excess of $1,000,000, including Senator John Kerry of Massachusetts. A great deal of Congressional wealth is derived from investments.
(this is the end of the information from USA Today)

In addition to the staggering number of drug companies which presents another profiteering issue all together, General Electric and Lucent are on the Center for Public Intergrity's list of the top contractors in Iraq and Afghanistan.