If your portfolio didn't pop in 2010, you're not alone.

The Dow, S&P 500, and Nasdaq all managed to post percentage gains in the low double digits in 2010. That's pretty good for most investors, but there were naturally several stocks that did a lot better.

Let's take a look at five stocks that more than tripled last year. Some of the names may surprise you:

Company

12/31/09

12/31/10

Gain

Travelzoo (Nasdaq: TZOO) $12.29 $41.38 237%
Rare Element Resources (AMEX: REE) $3.88 $16.06 314%
Molycorp (NYSE: MCP) $12.85* $49.90 288%
Netflix (Nasdaq: NFLX) $55.09 $175.70 219%
Las Vegas Sands (NYSE: LVS) $14.94 $45.95 208%


Source: Yahoo! Finance. Prices adjusted for dividend distributions. 
*Closing price on July 29, Molycorp's first trading day after its IPO.

Travelzoo is the travel deals publisher behind the Travelzoo Top 20 weekly emails, which go out to millions of opt-in recipients. Shares were meandering in the low teens until its summertime announcement of a Groupon-esque initiative, in which it would begin selling vouchers to travel-related experiences. It's been picking up momentum in that direction lately.

Rare Element Resources and Molycorp took off as rare-earth stocks exploded last year. Things were going well even before China declared its intent to limit rare-earth exports this year. China's decision to keep more of the minerals it mines to meet its own growing demand will naturally move global prices higher.

Netflix came into its own in 2010, with more of its subscribers moving toward higher-margin streaming. Let's just hope the company can keep content costs in check. Investors considered the stock a recession play, given its ability to attract homebound couch potatoes during the economic downturn. However, when subscriber growth began to accelerate in 2010, the market pounced on Netflix as an all-weather winner.

Casino operator Las Vegas Sands gained steam as growth investors got pumped over its Asian properties. Will the red-hot Macau market continue to sizzle, or is this bubble about to pop? Las Vegas Sands is willing to bet on the former.

What stock on this list do you think will climb even higher in 2011? Share your thoughts in the comment box below.