Another crazy gold bug has finally lost his last remaining marble ... or so it might seem convenient to conclude.

Can there be any other reasonable explanation behind this Fool's selection of Silver Wheaton (NYSE:SLW) as his top pick for 2010? Talk about pressing your luck!

Bolstered by some remarkable earnings, Silver Wheaton shares have appreciated by 141% so far in 2009, and more than 500% from the worst levels of that 18-month correction in precious-metal prices.

This low-cost silver producer with the unique business model became my best stock tip of 2008, after I highlighted its insanely cheap valuation on the exact day that shares experienced a dramatic reversal of fortune.

As precious-metal prices continued to surge throughout 2009, and Silver Wheaton grew stronger through strategic acquisitions -- gobbling up smaller competitor Silverstone Resources and securing the landmark Pascua-Lama silver stream deal with Barrick Gold (NYSE:ABX) -- this Fool consistently touted Silver Wheaton as the superior choice for silver exposure. Indeed, even Fool favorite Hecla Mining (NYSE:HL) and my runner-up Coeur d'Alene Mines (NYSE:CDE) have been edged out by Silver Wheaton's untarnished performance in 2009.

Why risk a record like that by extending the bullish call into 2010 with the selection of Silver Wheaton as my official top pick? Would this Fool have a better chance of success if he simply doubled down on his 2009 selection of gold miner Agnico-Eagle Mines (NYSE:AEM)?

I must have a screw loose, right?
Ouch ... easy there with the spurious presumptions of insanity, please. What's that? I made those presumptions? Darn those pesky voices!

Speaking of lunacy, and in the interest of intelligent discourse, could we consider burying the term "gold bug" once and for all as we approach the new year? I refute the label largely because of the illogical and derogatory associations that it conjures. From my background in anthropology, I know that prevailing attitudes are fluid over time, and my calls for $2,000 gold and $50 silver are no longer met with the same degree of dismissive incredulity as they were when I issued the very same projections back in 2007.

Even investors who are nervous about gold investments can find relative safety in silver at this stage. Above-ground supplies of physical silver are minuscule, so even minute fluctuations in demand could send sizeable shockwaves through this roughly $10 billion physical market. Fools are encouraged to ponder the slingshot effect, a term that I coined last April to explain the immutable relationship between prices of gold and silver despite silver's frequent lags and near-term dislocations. For an idea of how far that slingshot is currently stretched, the historically anomalous 64:1 ratio between the two metals provides a stark reminder that silver has not even broken beyond its March 2008 high above $20 per ounce.

Those who may be convinced that gold and silver prices will plummet in the face of resounding economic recovery are reminded to consider that annual industrial demand from manufacturers of handheld devices alone represents about 30% of 2008's total mined production. Frankly, silver is poised to seek higher prices within a wide range of economic scenarios.

The unbreakable investment case for Silver Wheaton
The beauty of my selection of Silver Wheaton is that considerable upside potential exists for these shares whether or not silver triples in price from present levels as I anticipate. With an essentially fixed production cost of about $4 per ounce of silver, the silver stream specialist enjoys a cozy operating margin at today's silver price and is already mulling the inception of a dividend, as free cash flow is expected to rise like a river in flood stage. With Goldcorp's (NYSE:GG) Penasquito mine entering commercial production momentarily, Silver Wheaton remains in the early stages of a production growth spurt that will take it from 11 million ounces in 2008 to more than 40 million ounces in 2013.

Back in July, I issued an open invitation to Fools to find flaws in my glowing assessment of Silver Wheaton's prospects, and to this date, I have yet to encounter an argument that shook my belief in the analysis that I have presented throughout the many articles linked above.

Understanding the valuation case for Silver Wheaton requires a step back from the near-term glory of its recent run. Despite having doubled attributable proven and probable reserves during 2009 with enormously transformative strategic acquisitions, these shares have yet to surpass their March 2008 high of $19.54. Trading at just more than 17 times projected 2010 cash flow, the market has yet to deliver anything approaching full value for Silver Wheaton shares at today's silver prices -- let alone considering the potential boost from strengthening silver prices or additional acquisitive growth in 2010.

Combined attributable silver reserves and resources equate to five ounces of silver for every share of Silver Wheaton stock -- a sort of underground vault of physical silver supply with a present market value of about $85 per share before costs. Since those costs are essentially fixed, projecting profit and cash flow for multiple silver price scenarios is a relatively simple process that I think Fools will enjoy tackling on their own. I expect long-term prices to trend substantially higher, but even using today's silver prices, I see room for shares to double once more before we reach fair value. Underperforming silver miners like Pan American Silver (NASDAQ:PAAS) look attractive on valuation as well, but Silver Wheaton's prospects simply outshine them all.

It's time for you to join hands with us freaky gold-bug Fools from the lunatic fringe, and vote for Silver Wheaton as your pick for the best stock of 2010.

Which is the best stock for 2010? See all 13 candidates here.