FORTUNE — Millennials are the prime target for many businesses today. While some companies bomb in their attempt to reach this fickle generation, some brands have nailed it and are taking major profits to the bank.

Who, exactly, are these Millennials? Anyone 8 to 26 years old , born between 1984 and 2002. Millennials are tweens, teens, and young adults.

The following are just a few brands getting it right in terms of marketing to Millennials.

MTV

Just a few years ago, MTV’s ratings were sinking, and a lot of people had had enough of the single-note tonality of the network. So, MTV did what it does best. It innovated. Sure, Jersey Shore and other low-brow shoes have helped the Viacom (VIA) network reinvent, but MTV also delivers the anti-bullying PSA campaign “It’s A Thin Line” to teenagers.

Coca-Cola

Coca-Cola (KO) marketers love to say that Coke is “125 years young,” and it’s that mentality that puts Coke ahead of its competitors. Coke sells 1.5 billion servings per day. In a presentation at a TED conference, Melinda Gates noted that we can all learn something from Coke’s marketing strategies, and she highlighted three areas in which the brand excels: real-time data, a plugged-in global network of entrepreneurial talent, and standout marketing.

Teen Vogue

A style authority for girls and young women who aren’t ready for Vogue, Teen Vogue leads in ad pages over venerable Seventeen. Teen Vogue also plays backdrop for the hit MTV show The Hills. Stars Lauren Conrad and Whitney Port interned at the mag.

Old Navy

The Gap (TK) division’s “trendy offerings at fair prices” (IS THIS A PHRASE THE CO. USES?) was a marketing tool even before the recession–and most appealing to budget-crunched Millenials. Old Navy ranks second to Target (TGT) on our Brand Passion Index, OUR WHATKINDOF SURVEY which measures consumer insights around popular consumer brands.

Apple

Apple (AAPL) computers consistently rank higher than PCs on the cool factor, even though almost 70% of our surveyed buzzSpotters® own PCs. Here’s the thing: Millennials can’t afford such expensive products from the brand they love the most. It’s not like Apple is hurting, but imagine Apple could capture that revenue from Millennials. Meanwhile, the iPod is the MP3-playing device of choice. Poor Zune.

Nintendo

After Sony (TK) dominated with PlayStation and Microsoft (MSFT) with Xbox, Nintendo once again reigns supreme with Millennials. Ourrecent buzzSpotter® tween survey showed that over 70% of respondents own a Wii, while an additional 21% own a DS or DSi. That’s a lot of Nintendo for one tween.

Nike

Nike’s (NKE) iconic logo and simple “Just do it” has always resonated with Millenials In a recent global study of 16,000 teens by Teenage Research Unlimited, Nike ranked in the top three brands among teens in 11 of 15 countries. Nike knows that Millennials are elusive, that you have to work hard for their dollar every day. There is no finish line.

T-Mobile

T-Mobile is the creator of the Sidekick, the most popular phone with teens for years. Recently acquired by AT&T (ATT), T-Mobile is rolling out new teen initiatives like DriveSmart, which aims to prevent distracted driving. That makes the company popular with parents, the ultimate consumers when it comes to teens and cell phones.

Axe

Though Old Spice launched a juggernaut campaign in 2010, Axe still rules with Millennials. Launched by Unilever (TK) as a deodorant brand in 1983, the brand now includes shower gels, aftershaves, skin care, colognes, and shampoo. Axe ad campaigns are tongue in cheek. “World’s Manliest Rituals,” in partnership with web site Funny or Die, further Axe’s snarky approach.

Louis Vuitton

For tweens, it’s aspirational; for teens, it’s inspirational. Marketers can learn a lot from Marc Jacobs, WHOSE ROLE IS WHAT. Whether through a faux graffiti collection or Kanye West rapping about the brand, Louis Vuitton resonates with Millenials. Just because teens can’t afford a $30,000 Louis Vuitton trunk doesn’t mean they won’t plunk down $70 for a charm. If you get them while they’re young, they’ll be loyal for life.