It's no secret Warren Buffett likes the value proposition of Wells Fargo ( WFC ). The current market value of Berkshire Hathaway's ( BRK.B ) stake in Wells Fargo is about $13 billion. But Wells Fargo isn't his only bank crush. Berkshire Hathaway's stock investment portfolio also includes a chunk of U.S. Bancorp ( USB ) with a current market value of $2.6 billion.

Granted, that's not exactly an outsize bet given that Berkshire's investment portfolio had a market value of $89 billion at the end of the first quarter. But U.S. Bancorp, the parent of U.S. Bank National Association, the fifth largest commercial bank in the country, is actually outperforming Wells Fargo lately-and to be clear, Wells Fargo has been on a roll of its own, as seen in this stock chart .

USB data by YCharts

U.S. Bancorp even manages to best Wells Fargo on return on assets . . .

USB Return on Assets data by YCharts

. . .as well as return on equity.

USB Return on Equity data by YCharts

Management reiterated in its second quarter conference call that those ratios are at the low end of long-term targets of 1.6%-1.9% on return on assets and 16%-19% for return on equity.

In a lot of ways, U.S. Bancorp ($353 billion in total assets) is sort of the mini-me version of Wells Fargo ($1.336 total assets). Like Wells Fargo the focus at U.S. Bancorp is on old-fashioned banking -- bring in deposits, make loans , charge fees -- rather than looking to generate profits from aggressive in-house trading, à la JPMorgan ( JPM ).

The plain vanilla route seems to be a pretty good business model for U.S. Bancorp. In the second quarter it reported an 8% jump in net revenue and earnings per share rose 18.3%.

USB Revenue data by YCharts

Overall fee revenue increased 9.7% in the quarter. That's impressive given that it includes a near 18% decline in revenues from credit card and debit fees federal regulations, courtesy of new federal regulations.

U.S. Bancorp is also positioned to ride the housing recovery. Overall loan volume at U.S. Bancorp rose 7% in the second quarter compared to a year earlier; the residential mortgage slice grew at nearly three times that rate. And the charge-off rate for bad residential mortgages fell to 1.12% compared to 1.46% in the second quarter of 2011.

Financial Crisis? What financial crisis?

With a strong balance sheet, the Minneapolis based regional bank was able to use the financial crisis as a growth opportunity, taking failed banks off the FDIC's hands and making acquisitions as well.

USB Total Assets data by YCharts

And despite a solid increase in the company's value, it's still trading at a pretty low PE ratio .

USB PE Ratio data by YCharts

Just the sort of chart Buffett would love.

Carla Fried is an editor for the YCharts Pro Investor Service which includes professional stock charts , stock ratings and portfolio strategies .