For those willing to endure the inevitable price roller coaster, there's tremendous opportunity in hyper-growth biotech stocks. But you have to pick the best stocks if you're going to generate market-beating returns. So we asked each of our analysts a simple question: "What is the best biotech stock for your portfolio?" Read below for their picks.

Todd Campbell: If you're new to biotech and looking for a great growth company for your portfolio, Gilead Sciences (NASDAQ:GILD) should be at the top of your list. That's because few companies have the biotech chops to match it.

Gilead is a Goliath in HIV treatment, boasting an HIV product portfolio that includes five different medicines that could hit billion dollar blockbuster status this year. Last year, the companies HIV drug sales totaled more than $9 billion and that momentum is building. During the first six months of this year, sales of those drugs are up nearly 10%.

But it's not just Gilead's dominance in HIV -- its Atripla and Truvada are the top two drugs prescribed for HIV in the U.S. -- that should have Gilead on your list.

The company's multibillion blockbuster hepatitis C drug franchise is fattening up Gilead's balance sheet, too. Since December, Gilead's cash hoard has jumped from a bit over $2.5 billion to more $9.5 billion exiting the second quarter. That growth is thanks its breakthrough hepatitis C treatment, Sovaldi, raking in more than $5 billion in the first half of 2014. With a likely FDA approval of its next generation Sovaldi (paired up another Gilead drug, ledipasvir) on tap, Gilead's market share leading position should continue through 2015.

George Budwell: One of my personal favorite names in biotech these days is the little-known French company Flamel Technologies SA (NASDAQ:FLML). Although this stock has more than doubled in the past year, I think Flamel still has plenty of upside remaining for investors willing to take the longer view -- and who aren't risk-averse (small-cap biotechs are speculative and risky as a rule).

My optimism is based on two catalysts. First off, we have the compelling story of Flamel's FDA-approved Bloxiverz (neostigmine methylsulfate injection) to bank on to drive major growth going forward. What's key to note is that the FDA has now banned all unapproved versions of the drug, essentially giving Flamel 100% of this growing market, once other manufacturers run out of stock.

According to data from S&P Capital IQ, analysts estimate that Flamel's revenue will quintuple over the next two years based mainly due to a ramp-up in Bloxiverz sales. But I wouldn't be surprised if Flamel also decides to raise Bloxiverz's price now that is has exclusivity, driving even higher revenue and earnings growth. 

Looking further out, Flamel offers investors a second, albeit much more speculative opportunity with its Micropump technology that could rival Jazz Pharmaceuticals' flagship drug Xyrem in the narcolepsy market. With a forward P/E (based on 2015 estimated EPS) of less than 12, I think the market hasn't fully appreciated the potential upside of the stock.

Sean Williams: If there's one word that encompasses why Celgene (NASDAQ:CELG) should be a strong consideration for any biotech investor's portfolio, it's "organic." While Celgene has more than two dozen collaborative partnerships with the likes of OncoMed Pharmaceuticals, Agios Pharmaceuticals, and bluebird bio, just to name a few, it's the company's internal growth capacity that makes it so unique.

Label expansion is a big component to Celgene's success, with blood cancer drug Revlimid expected to expand into a number of new indications in the coming years, including first-line follicular lymphoma, and newly diagnosed multiple myeloma. Of course, Revlimid will have to be successful in clinical studies for this to happen, but the drug is already on pace to top $5 billion in sales this year, so it's looking very likely.

Cancer drug Abraxane and inflammation drug Otezla are also expected to play a key role in providing additional labels, with Abraxane being targeted at first-line triple-negative breast cancer, and Otezla at the monster rheumatoid arthritis indication.

With the company expecting these additional indications to essentially double its revenue between 2013 and 2017, all while valued at a mere 12 times 2017's EPS projections, I think it a wise idea for investors to give Celgene serious consideration moving forward.

Sean Williams has no position in any stocks mentioned. Todd Campbell and George Budwell own shares of Gilead Sciences. The Motley Fool recommends Celgene and Gilead Sciences and owns shares of Gilead Sciences. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.