Unusually on a buoyant day for equities, tobacco is the best performing sector today.This is due to a warm reception for Imperial Tobacco's full-year results.The Gauloises and West firm topped market forecasts with its full year profits, and took a big bite out of its debt mountain.The only other stock in the sector, British American Tobacco, is also posting good gains. Oil and gas producers have also gushed ahead. Among the risers are beleaguered oil giant BP, which comfortably beat third quarter profit forecasts and is considering upping the amount of capital expenditure it has budgeted for next year.Another big hitter, BG Group is also wanted after it grew third quarter earnings by 27% and now thinks there's an extra 2.7 billion barrels of oil equivalent (boe) at its oilfields in the Santo Basin offshore Brazil, 34% more than previous estimates.Among smaller companies, Falkland Islands-focused Desire and Providence Resources are higher after exploration updates.Top performing sectors so far todayTobacco 28,638.00 +2.20%Oil & Gas Producers 7,858.99 +2.07%Forestry & Paper 5,628.03 +1.85%Mining 24,803.19 +1.57%Industrial Engineering 6,115.76 +1.35%Bottom performing sectors so far todayAutomobiles & Parts 4,056.54 -2.42%Technology Hardware & Equipment 554.12 -1.16%Industrial Transportation 2,329.96 -0.62%Construction & Materials 3,641.02 -0.42%Alternative Energy 3,025.85 -0.35%