6. Consol Energy ( CNX) is a diversified fuel producer and services provider in the Eastern U.S. By the end of Dec. 2010, the company's proved gas reserves were 3.7 trillion cubic feet (Tcf), increasing 95% from 1.9 Tcf reported at the end of 2009. Of the 3.7 Tcf proved reserves, 52% are proved developed reserves (PDP) and 48% are classified as proved undeveloped. The proved undeveloped reserves increased 107% in 2010, whereas the PDP increased 86% during the same period. Regarding Marcellus Shale, J. Brett Harvey, the company's CEO, said, "We saw solid growth in our coal bed methane reserves and a nice jump in our Marcellus Shale PDP bookings from our 2010 program. The reserves from our 2010 Marcellus Shale program averaged 5.5 Bcf per well. When you consider that our laterals averaged 3,400 feet, this means that we booked about 1 Bcf of reserves for every 600 feet of lateral." The stock rose 24% in the last one year and analysts expect a further upside of 13% in the next one year with buy ratings of 68%. The stock is trading at 12 times its estimated 2011 earnings.