Warren Buffett once said, "Our favorite holding period is forever." Although "forever" may be an exaggeration (even for Buffett), it would certainly make investing simpler if you could buy good stocks and then mentally lock them away in your portfolio. But not every stock is a keeper.

We went looking for financially healthy, well-managed companies with an ironclad lead in their industries and promising prospects for growth. These are the kind of winning businesses you can buy no matter what the overall market is doing, the ones that smart investors buy more of when prices dip.

Some of the firms on our list may surprise you; others are no-brainers. They aren't stumble-proof. Every company has its weak spots. But we think these have enough potential for gains to overcome those risks. Although they look like good buys now, a bargain share price wasn't our top priority. If the firm is a powerhouse and your commitment is long term, sometimes it's okay to pay a premium. "Price is what you pay," as Buffett also once said. "Value is what you get."

Accenture: Reinventing Consulting

Courtesy Accenture

Market value: $110.0 billion

Earnings growth rate: 10.0%

Your image of what a consulting firm does is probably outdated. Gone is the era when companies like Accenture (symbol , $163) might have installed a new software system and called it a