It's a new week, which means it's time to check the most interesting insider purchases. After reading through numerous filings using insider tracking tool Form 4 Oracle, here are my top five today.

The week's buying

Company

Closing Price 5/7/08

Total Value Purchased

52-Week Change

Callaway Golf (NYSE: ELY)

$14.07

$169,914

(21.1%)

Coca-Cola Enterprises (NYSE: CCE)

$22.09

$678,050

(0.7%)

Enterprise Products Partners (NYSE: EPD)

$32.29

$2,045,803

7.7%

Markel Corp. (NYSE: MKL)

$429.20

$41,800

(8.6%)

Verizon Communications (NYSE: VZ)

$38.89

$760,000

(0.3%)

Sources: Fool.com, Yahoo! Finance, Form 4 Oracle, SEC filings.

Markel still remarkable?
Insurance companies aren't exactly all the rage right now, thanks to the credit crunch. But what about Markel, a specialty insurer that Foolish colleague Philip Durell, chief advisor for our Motley Fool Inside Value service, calls "remarkable"? Quoting from the special report he issued in November:

Markel is not as undervalued as some of my Inside Value recommendations, but I believe that even at fair value it deserves a spot as a core holding in your portfolio. It is one of the few insurance companies that exhibit the kind of underwriting discipline, and some of the investment acumen, found at Warren Buffett's Berkshire Hathaway (NYSE: BRK-A) (NYSE: BRK-B).

Talk about an endorsement.

Markel was trading for $479 a share when Philip wrote that. A 10% haircut since could be due to weak underwriting profits and investment losses in the first quarter. Having a large position in Citigroup (NYSE: C) probably didn't help.

Yet our 100,000-plus-strong Motley Fool CAPS community hasn't lost faith:

Metric

Markel

CAPS stars (out of 5)

*****

Total ratings

1,770

Bullish ratings

1,739

Percent Bulls

98.2%

Bearish ratings

31

Percent Bears

1.8%

Bullish pitches

285

Bearish pitches

8

Data current as of May 7, 2008.

What I like about Markel is its historical ability to produces gobs of cash from its core business -- $479 million in free cash flow over the trailing 12 months -- and produce double-digit rates of return on its available capital.

That's even true over the trailing 12 months, when Q1's underwhelming underwriting results and investment losses dropped ROIC for the quarter to just 4.5%. If you believe that management can right the ship, as I do, then returns should follow.

Management appears to agree. Chief Financial Officer Richard Whitt last week spent $41,800 to pad his position in the stock. Or, in simpler terms: The numbers guy likes the numbers.

As a whole, insiders own nearly 8% of the company. And, as recently as December, institutional investors I really respect -- including Chuck Royce of the Pennsylvania Mutual (PENNX) fund and Peter Doyle and Murray Stahl of Kinetics Paradigm (WWNPX) -- were buying shares. Who am I to argue with them?

There's your update. See you back here next week, when we dig through more insider filings in search of the next home run stock.

Get the inside scoop on stocks of all sizes with related Foolishness:

Pennsylvania Mutual is a Champion Funds pick. Berkshire Hathaway is a recommendation of both the Inside Value and Stock Advisor services. Enterprise Products Partners is an Income Investor pick. Coca-Cola is an Inside Value selection. The Motley Fool owns shares of Berkshire Hathaway.

Fool.com and Rule Breakers contributor Tim Beyers, who is ranked 14,930 out of more than 100,000 participants in CAPS, owned shares of Berkshire Hathaway at the time of publication. Find Tim's portfolio here and his latest blog commentary here. The Motley Fool has a disclosure policy.