Here's the final installment in Fooling the Idols, season six. We're down to the wire with only two horses left in the race. Who trots away with the victory, and who comes up a little hoarse? I'm not Ryan Seacrest, but I did stay at a fancy motel last night.

The contestants are fighting dry throats with their favorite soft drinks. In the tall corner, we have Jordin Sparks sipping a Coca-Cola (NYSE:KO), the official soft drink of American Idol. And here in the funky corner, Beatbox Blake is nursing a pitcher of Pepsi (NYSE:PEP).

The contestants
Jordin's weakness and defining attribute is a one-note repertoire -- heart-tugging ballads make her look and sound like a superstar, but things can get shaky outside of that comfort zone.

Funny how well that matches her drink. Coke taught us all to sing in perfect harmony many decades ago. Reformulations and new products come and go, but in the end, it's the core Coke brand that carries the day for this global headliner.

Pepsi has chosen a different strategy, diversifying into Frito-Lay's snack foods and Quaker Oats breakfast fare. And when Pepsi asks us to "Dare for more," Blake takes that to heart. Who else would put beatboxing drum breaks into classic rock songs?

The game
These giants have beaten all comers and stand head, shoulders, and hips above the rest. It's not for a lack of challengers, either. Cadbury Schweppes (NYSE:CSG) has the 7-Up and Dr. Pepper brands in the game, neither of which looks particularly threatening to the top two. Upstarts like Jones Soda (NASDAQ:JSDA) pop up every now and then and surge in popularity, but none has stood the test of time.

The rivalry can go either way, depending on how you define it. If it's cola versus cola you're after, Pepsi can take the occasional local market and is making a strong run for the prize in North America these days, but Coke remains the global leader. If you expand the field to soft drinks in general, Sprite and Fanta can take Sierra Mist and Mountain Dew in a worldwide market share fight any day.

The picture changes a bit when you start folding in products like sports drinks, where Pepsi's Gatorade looks fairly safe from Coke's Powerade challenge. Bottled water pits Aquafina against Dasani, and fruit juices have Tropicana going up against Minute Maid. These are all respectable brands, but it's hard to call a winner -- and the competition now includes tap water and backyard fruit trees.

Let's not even get into the energy drink explosion. Coke has its own Full Throttle and distributes Rock Star, while Sobe Energy carries the Pepsi banner. Both have some serious catching up to do, however, if they want to beat incumbent No. 1 Red Bull or its only serious rival, Hansen Natural's (NASDAQ:HANS) Monster Energy.

Finally, there's the variety of not-so-liquid snacks from Pepsi's brand stables. That's a lower-margin business than pure drink syrups, but it's also a way to reach customers who never visit the bottled drink aisle in their supermarkets. Diversification gives Pepsi a broader base of operations and new growth opportunities, at the cost of Coke's pure-play efficiencies. It can be a simple choice or a very complex picture, depending on your criteria.

Final Foolish farewell
As you can see, the cola wars make for tough calls. I'm a Coca-Cola man myself, but I can certainly see why you might invest in Pepsi. It's a specialist vs. a funky two-sport star, and both would serve your portfolio well.

As for tonight's vote, it's the same story over again. Will America choose a sweet-voiced balladeer or a box full of surprising beats? Either way, the winner auditioned in Seattle.

Vote early, vote often! Foolcrest -- out!

Further Foolishness:

Coca-Cola is a Motley Fool Inside Value recommendation. Read all about it with a free 30-day trial subscription.

Fool contributor Anders Bylund owns shares in Coke and Hansen but holds no other position in any of the companies discussed here. Jordin may be six feet tall, but Anders still holds a five-inch advantage over her. You can check out Anders' holdings if you like, and Foolish disclosure will make you a superstar.