Exchange-traded funds have hit the investing world by storm. But with hundreds of different ETFs to choose from, how can you make the best choice for your portfolio?

To help you answer that question, we asked some of our Motley Fool analysts to weigh in with their opinions about which ETFs they like right now. They also gave their views on some popular ETFs that might not be your best bet. Read on to see their ideas.

Amanda Kish, analyst, Champion Funds Quarterly
There are two keys to picking good ETFs: price and diversification. Since you're not paying for manager expertise, you want the cheapest fund you can find to get the job done. Likewise, broad-based funds that invest in fairly wide sections of the market are usually appropriate for most investors. Vanguard Dividend Appreciation ETF (NYSE: VIG) gives investors the exposure they need to dividend-producing stocks, with a price tag of just 0.18% a year.

On the other hand, leveraged ETFs carry high costs and big risk. One fund that serves as a good example of everything that is wrong with these investments is the Direxion Daily Developed Market Bull 3X Shares (NYSE: DZK), which tries to triple the daily return of the MSCI EAFE Index. Even a small decline would really sock investors -- and with its 1.34% expense ratio, you can't afford to stick with the ETF for long. Funds like these are more suited to frequent day trading than long-term investing.

John Rosevear, Motley Fool contributor
After some recent weakness, gold prices are heading back toward all-time highs. With the debt standoff in the U.S. and several eurozone governments in trouble, gold could skyrocket -- or, if these fears come to naught, come crashing down with a thud like one of those Acme anvils that used to bedevil Wile E. Coyote.

ETFs -- specifically, SPDR Gold Shares (NYSE: GLD), and PowerShares DB Gold Double Short (NYSE: DZZ), which theoretically goes up $2 for every $1 drop in the price of gold -- are probably the best ways for individual investors to get in on the game.

So which would I pick? Neither. There's just too much downside risk to betting the wrong way. Gold's a gamble rather than an investment right now, and I plan to stay on the sidelines munching popcorn as the drama unfolds.

Speaking of popcorn, I'd recommend another commodity ETF that doesn't get a whole lot of attention -- the Teucrium Corn ETF (NYSE: CORN), a "pure play" fund that holds corn futures. The case for corn is pretty simple: Demand is rising faster than crop yields, and stocks of the grain are falling. That suggests strong potential for price appreciation over the next few years -- with much less drama than we're likely to see in the land of precious metals.

Selena Maranjian, Motley Fool contributor
It's a little hard to believe, but fast-growing tech companies are trading at bargain prices these days despite their exciting prospects. Although you can cherry-pick among tech leaders, the easier way to invest in a broad basket of tech stocks is through a sector ETF.

The Technology Select Sector SPDR (NYSE: XLK) ETF, which includes more than 80 tech companies, has extremely lost costs of just 0.20%. Along with that low fee comes a strong track record, with the fund beating the S&P 500 over the past three and five years. With so many big tech names seemingly undervalued, this is a promising fund to own.

Be choosy with your technology funds, though. The B2B Internet HOLDRs (NYSE: BHH) fund may have an appealing title, but it holds just two stocks, with 91% of its assets in Ariba. It won't give you the diversification you want from an exchange-traded product. Stick with broader-based ETFs like SPDR Technology, and you'll get full exposure to the tech trend.

Learn more
Get more information about great ETFs from The Motley Fool's free special report, "3 ETFs Set to Soar During the Recovery." With selections including technology and commodity ETFs, you won't want to miss it.

Fool contributor Dan Caplinger compiled this roundtable, and he doesn't own shares of any of the stocks or ETFs mentioned. John owns shares of Teucrium Corn Fund. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Fool's disclosure policy makes you feel like a knight at King Arthur's roundtable.