If you're like most seasoned investors, you've run across some truly great companies that you'd love to own -- if only the stock were a little (or maybe a lot) cheaper. Sometimes, the right thing to do is to wait: Keep an eye on the stock until the market's cycles bring its price down to a more comfortable range. 

That happens to most stocks, sooner or later, and many of us keep lists of stocks to look at if and when the market puts them on sale. We asked three of our contributors to name the best stocks on their buy-on-sale lists right now. Their choices? Intuitive Surgical (NASDAQ:ISRG), Ferrari (NYSE:RACE), and MercadoLibre (NASDAQ:MELI). Here's why. 

A leader in robotics

Keith Noonan (Intuitive Surgical): Robotics is an area of the technology sector that presents enormous opportunities for investors, and Intuitive Surgical stands out as one of the most promising companies in the fast-growing space. Intuitive's machines are used by surgeons to enable greater precision and flexibility than human hands would otherwise allow and enable minimally invasive cuts for surgeries including prostatectomies, hysterectomies, and hernia repair. Check out this video from the company's YouTube channel featuring one of its machines stitching a grape back together to get an idea of what Intuitive's da Vinci surgical robots can do.

The company's business model isn't limited to the sale of devices, either. It also sells razors and blades used in surgeries, which gives the company recurring revenue streams. Sales of tools and accessories accounted for 71% of revenue in the last fiscal year and 77% of revenue in the last quarter. 

The stock has gained roughly 33% year to date and increased 12% following its April 18 earnings release. Last quarter, the number of surgeries performed by da Vinci devices increased 18% from the prior-year period, and the company is enjoying a first-mover advantage in medical robotics that has the potential to give way to a long-term moat because its top-of-the line technologies are becoming the standard in the field. 

An expanding market for its existing devices and the potential to evolve into new technologies give Intuitive Surgical substantial growth potential, but strong earnings results and increased interest in the company have also made the stock pricier. Intuitive shares trade at roughly 36 times forward earnings estimates, and investors might want to pounce when there's some pullback.

A Ferrari Formula One race car on a track.

Ferrari is an automaker, a luxury brand, and a sports team -- with fat profits and a stock price to match. Image source: Ferrari N.V.

A car company unlike any other

John Rosevear (Ferrari): A lot of investors have a tough time with automakers. Operating margins tend to be in the single digits, costs are very high, competition is fierce, disruption is lurking -- and those already narrow margins get squeezed to nothing (or worse) when the economic cycle turns downward.

But in so many ways, Ferrari is not like any other automaker:

  • EBIT margin was a whopping 21.5% in the first quarter, and that wasn't a fluke;
  • Production numbers are tiny, under 10,000 a year, so it doesn't have the huge fixed costs of big automakers;
  • Its brand, history, mystique, and, yes, jewel-like products all add up to a fat moat; 
  • Its ultra-wealthy customers are more shielded than most from the ups and downs of the economic cycle.

Ferrari also has a path to what could be significant profit growth. While it limits annual production to preserve its mystique (and pricing power), CEO Sergio Marchionne thinks that the company can raise production somewhat over the next few years without harm, thanks to growing demand from newly wealthy folks in places like Russia and China. Ferrari also builds special limited-run models from time to time that are generally priced well into seven figures -- with correspondingly huge profit margins. On top of that, its fabled Formula One racing team generated over 120 million euros in sponsorship revenue in the first quarter. 

So what's not to like? As with everything else having to do with Ferrari, if you want to own the stock, you'll pay for the privilege.

RACE Chart

RACE data by YCharts.

Ferrari's stock has had quite a run over the last year. Right now, it's expensive, with a trailing price-to-earnings ratio of more than 36. It's a little cheaper if we look ahead, at about 28 times expected 2017 earnings, but it's still (fully) priced like a luxury company. 

That's arguably a fair valuation for this unique automaker, but it's still steep. Ferrari's cars may never go on sale, but if and when the stock does, I'm in.

The most powerful force in Latin American e-commerce

Keith Speights (MercadoLibre): Most of the stocks I own make the lion's share of their revenue in the U.S., but I'd also like to add a stock with primarily international exposure to the mix. MercadoLibre (NASDAQ:MELI) looks like a perfect fit.

The company is without question the most powerful force in Latin American e-commerce. MercadoLibre operates a massive online commerce ecosystem spanning 19 countries in Central America and South America. This ecosystem includes an online marketplace that connects buyers and sellers, classifieds service, electronic payments solution, advertising program, web stores, and a shipping service.

MercadoLibre's revenue has more than doubled over the past five years. Its earnings have grown also, but not nearly as fast. However, that's mainly because MercadoLibre has poured a lot of money into its sales and market efforts and into product and technology development.

The growth potential for the company looks solid. Latin America has a population of more than 610 million people. The middle class is expanding in many countries in the region. Latin America also claims one of the fastest-growing internet penetration rates in the world. 

MercadoLibre stock isn't cheap, though. Shares currently trade at 76 times trailing-12-month earnings and 41 times expected earnings. I'll definitely be watching for this promising Latin American stock to present a buying opportunity in a pullback.  

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.