It might not be obvious to the casual observer, but right now, today, Allstate (NYSE:ALL) stock offers one of the best values available in the insurance industry. Why?

Three reasons.

Allstate stock is cheap
When you stack up Allstate stock against two of its rivals in property and casualty insurance -- Progressive (NYSE:PGR) and AIG (NYSE:AIG) -- it's clear that Allstate is one of the cheapest options out there. Its 10.6 price-to-earnings ratio is 8% below the P/E of AIG. It’s a whopping 35% discount to the price of a share of Progressive.

And as is so often the case, with a low valuation comes a big boost in dividend yield. Allstate stock currently yields a tidy 2% dividend. That's nearly twice the payout at Progressive, and infinity-times-better than dividend-less AIG.

Allstate: bargain-priced growth
Why aren't investors paying up for Allstate stock (yet)? Part of the reason, one presumes, is that the stock's not exactly a whirlwind grower.

And yet, the discounted price on Allstate stock still doesn't make sense. If it's true that AIG may outgrow Allstate over the next few years, Progressive ... won't. Yet investors haven't yet woken up to the fact that they can buy a slightly faster growth rate in Allstate stock, and get it for a much lower price.

Allstate stock pays you best
Perhaps most important to investors, though, is the simple fact that out of these three big insurance concerns, Allstate is the firm generating the most cash from its business -- and it gives you the biggest free cash flow bang for your buck.

Measured by dividing a company's market capitalization (the price you pay for Allstate stock) into its free cash flow (the money your investment generates for you), Allstate offers investors quite simply the best free cash flow yield of these three companies. Put even more simply, for every dollar you invest in a share of Allstate stock today, you can expect the company to generate nearly 11.3 cents' worth of real cash profits on your investment.

ALL free cash flow yield data by YCharts.

Allstate may ultimately use this cash to pay you bigger dividends (it already pays a 2% dividend -- more than either Progressive or AIG), to buy back shares (increasing the size of your stake in the company for every share it takes off the table), or to reinvest in its business and maintain its lead over rivals for years to come. Any way you look at it, though, Allstate's ability to generate cash offers investors a great reason to invest.

And that, Fools, is the reason I think now's a great time to buy Allstate stock.