Perhaps if all the king's horses and all the king's men (and every central bank in Europe and the U.S.) put their wealth together, there might be enough to save Europe again. For skeptics like me, they're opportunities to see whether companies have earned their current valuations.

Keep in mind that some companies deserve their current valuations. Construction and management services company Shaw Group (NYSE: SHAW) skyrocketed earlier this week after Chicago Bridge & Iron agreed to buy the company for $3 billion in cash and stock. CB&I is making a big bet on a nuclear resurgence with Shaw Group being a primary constructor of nuclear power facilities.

Still, other companies might deserve a kick in the pants. Here's a look at three companies that could be worth selling.

Bio-check yourself before your wreck yourself
It's difficult enough finding a big pharmaceutical company that can regularly bring growth to the table, so imagine how difficult it is to find biotech companies that are stable and offer a dividend. Amgen (Nasdaq: AMGN) is one such company that was a gift from the heavens for shareholders about 10 years ago, but has been nothing short of a head-scratcher in recent years.

In Amgen's latest quarter, the company revised its guidance higher on a 10% increase in Enbrel sales and strong growth from some of its newer drugs. However, take a step back and take a look at how it's really generating this growth. Amgen, last year, announced a share repurchase program that would allow it to buy up to $10 billion worth of stock. That reduction in shares will boost EPS without the company actually growing its bottom line -- and that's precisely the reason I'm giving Amgen the thumbs-down here.

If you take a look at Amgen over the past five years, it has grown by a meager 1.8% annually with many of its larger revenue producers stagnating. Amgen's growth engine just hasn't been the same since pre-recession times. I'm not buying into Amgen's share buyback deception and want to see real growth from this biotech, otherwise I just as soon look toward "Big Pharma" which offers lower price-to-cash-flow ratios and higher dividend yields.

Not out of the woods just yet
Regional banking giant US Bancorp (NYSE: USB), took just a pittance of what larger national banks took in TARP loans in 2008; it avoided the subprime mortgage crisis with flying colors; and it has no exposure to the current European turmoil. In simpler terms, the company focuses on the boring aspects of savings, loans, trusts, and mortgage originations for homeowners and small businesses. It isn't glamorous, but it's resulted in 11 straight quarterly year-over-year profit increases.

So why would I recommend selling US Bancorp when the bank is so clearly outperforming its peers? Simply put: It's not out of the woods yet. Even though it lacks exposure to Europe, what goes on in Europe will affect spending and exports in the U.S., which could have a negative trickle-down effect to its customers. Although bad loan loss reserves dropped again, I don't see how that trend can keep up with GDP growth slowing and wage growth currently below inflation.

Perhaps the biggest damning factor to me is US Bancorp's valuation. I pretty much have a strict "sell them at two times book value" rule with banks. At about 1.95 times book value, US Bancorp is looking more than fairly valued. With many banks trading below book value (albeit with more inherent risks and exposure), I'd opt to take my chances elsewhere.

Don't count those chickens just yet
In this week's episode of "As the Liquid-Natural Gas Turns," we'll take a closer look at potential LNG powerhouse InterOil (NYSE: IOC) and I'll show you why traders are foolish (with a small "f") to be counting their chickens before they're hatched.

InterOil, operating out of Papua New Guinea, signed an agreement with its parliamentary government in 2009 to supply between 7.6 million and 10.2 million metric tons of LNG per year from its Elk and Antelope gas reserves. Also, as part of this agreement, InterOil was supposed to sell at least a 50.5% stake in its Elk and Antelope reserves to a major international company that regularly dealt with assets that were similar in size. Between the constant red tape from the Papua New Guinea parliament and InterOil's lack of wanting to divest its assets, and to keep control of its upstream segment, the deal between the two parties could very well fail -- yet investors are pricing the stock as if it's been delivering for two or three years.

Currently valued at more than 150 times trailing 12-month earnings and approaching 1,000 times forward earnings, InterOil is a long shot to succeed. The company, as of last week, is in negotiations with Royal Dutch Shell (NYSE: RDS-A) to divest up to 25% of its assets, but previous talks had not gone anywhere before with other oil companies, so why are we as investors to believe things will become better with a wave of the wand now? InterOil just isn't worth the risk.

Foolish roundup
After a week of big gains we're looking at big names that could be ripe to fall. Amgen hasn't really shown me the growth over the past five years while US Bancorp's valuation does it in. As for InterOil, red tape and hubris could take down this multi-billion dollar company.

I'm so confident in my three calls that I plan to make a CAPScall of underperform on each one. The question is: Would you do the same?

Share your thoughts in the comments section below, and to avoid investing in stocks like these, consider getting a copy of our special report: "The Motley Fool's Top Stock for 2012." In it, our chief investment officer details a play he dubbed the "Costco of Latin America." Best of all, this report is free for a limited time, so don't miss out!