A recent email exchange with an investor buddy of mine went something like this:

Jeff: What's the best energy company you know of between, say, $1 billion and $20 billion in market value? All sub-sectors count.

Toby: The best-run company? The best value?

Jeff: How about one of each?

Gee, thanks for the softball question there, Jeff. Very well. I'll give it a shot.

While the market capitalization caveat might seem broad, it actually constrains my choices a good deal. ExxonMobil (NYSE:XOM), arguably the greatest company in the history of the world, is obviously too big to fit the bill. So are independents like XTO Energy, EOG Resources, and Anadarko Petroleum. Meanwhile, longtime favorites Contango Oil & Gas and ATP Oil & Gas (NASDAQ:ATPG) are too small for consideration.

Among E&Ps, Chesapeake Energy (NYSE:CHK) is a contender for best value. It's tough to beat the company's shale exposure and expertise. That said, Chesapeake's low market cap belies significant financial leverage that caused trouble during the credit crisis, and potentially led the company to miss out on a killer acquisition.

Chesapeake management has a taste for excess, exemplified by CEO Aubrey McClendon's ridiculous wine collection, several thousand bottles of which were to be auctioned last month.  For best-run -- in which conservatism, shareholder-friendliness, and good governance are all key factors -- I would opt for Range Resources, Southwestern Energy (NYSE:SWN), or Ultra Petroleum.

Turning to the midstream players, I've been partial to Kinder Morgan Energy Partners (NYSE:KMP) since identifying it as a profit machine back in 2007. Having risen out of the ashes of Enron, the company has delivered 25% annual returns since inception (with distributions reinvested). Dollar-a-year man Richard Kinder and crew are serious capital allocators. The company also stacks up well in EnergyPoint Research's most recent customer satisfaction survey.

When it comes to oilfield services, you know I love my offshore drillers. Tops would be Noble (NYSE:NE), with Ensco International running a close second. Aside from being exceptionally well-managed, these companies also look quite cheap -- if not five-bagger cheap like Chesapeake.

Another standout in the services realm is Core Laboratories (NYSE:CLB). This rock jock was my pick for Best Stock for 2009. Through yesterday's close, the stock had delivered a year-to-date total return north of 80%. While Core Labs isn't obviously undervalued today, this may be the best energy company I know of, period. It's one that Jeff should get to know, and you should, too.