It would depend on your time horizon and risk preference. In the short term, you could ride the fluctuations in Gold stocks. Longer term most analysts are still bullish on energy seeing it hit $150 by the end of 2009. There are some good deals to be had with Suncor, Oilexco, and I don't think you could possibly go wrong with EnCana over a 2 to 3 year timeframe. The decline in the market has also significantly driven up the yield on a lot of the income trusts. If you are not averse to risk, HCI.UN is yielding approx 17%, and if you want a sin play as one of the other posters on this thread suggested, LIQ.UN also has a decent yield and owns a significant portion of the western Canada liquour market.
Personally, I am sitting in cash waiting for signs that some of the measures taken by the central banks are having an impact. There were apparently some loopholes that will allow banks to take advantage of the bailouts without helping main street America and that concerns me a bit.