Our Inc. 500 honorees this year include all types of companies, but few are as exciting as these product-driven brands. From the cult favorite Halo Top Creamery to the foot fetishists at Foot Cardigan, check out the coolest products being produced by the fastest-growing private companies in the U.S.

1. Fancy Footwork

Gnomes. Flamingos. Eight balls. This isn't a raucous night in Vegas--it's your sock drawer, if you happen to be a member of sock subscription service Foot Cardigan. "We didn't have a ton of money to compete with the big boys in the sock industry, and the subscription model had a relatively low barrier to entry," says co-founder and CEO Bryan DeLuca, a sock freak and former ad guy. For roughly $12 a month, subscribers to the Dallas-based startup can receive a variety of its cheeky footwear--from colorful Houdinis (no-show ankle socks) to Borings (solid up top, funky in your shoes) to Whipper Snappers (kids' socks). "When you cross your legs and your pant leg pops up," says DeLuca, "they say, 'Hey--I'm here for a good time.' " --K.R. and Burt Helm

2. Pimp Your Ride

When Jim Steen's steel fabrication business took a dip in 2009, he started hunting for a side hustle and noticed how many people had tricked out their trucks with custom bumpers. "They'd use cardboard to form a template and then go cut steel and weld it on themselves," he says. So the Lewistown, Montana, resident started his second company, selling weld-it-yourself kits online to truck lovers across the country. The kits are short on cardboard and long on customization: The bumper is cut to fit an exact make and model, and then loaded with add-ons like winch mounts, light holes, and pre-runner bars. The biggest hurdle to getting off the ground was getting the company's hands on different truck types, to measure each make and model minus its bumper. "If someone ordered a new make, we'd drive around town to look for that truck--then beg the person to let us borrow it," says Lacey, Jim's wife and co-founder. "It helped that we didn't use the word 'disassemble.' We say 'measure' and leave it at that."

3. Organic Growth

"We function like a high-fashion company, spending enormous amounts of time and money on trend and consumer research, traveling the world to trade shows in Italy, France, and Denmark, completing our product development 18 months out," says Bisser Georgiev. He founded not an apparel retailer but a houseplant startup. Apopka, Florida-based LiveTrends Design Group creates about 150 collections a year, incorporating living succulents into tabletop sculptures, tiny terrariums, and even jewelry. "We want to evoke the nostalgia for Grandma's kitchen with the fashion sense of Anthropologie."

4. High Tea

While working at the messenger bag company Timbuk2 in San Francisco, Andrew Chau and Bin Chen logged many hours at a nearby boba tea shop slurping on the milky, tapioca pearl-filled drinks of their childhoods. When that shop abruptly closed, Chau and Chen turned to YouTube to figure out how to make their own Taiwanese tea concoction--minus the artificial powders and sweeteners. After developing a recipe that uses premium loose leaf tea, organic milk, and brown-sugar syrup, they set up a pop-up shop in the back of a friend's ramen restaurant. A year later, says Chau, "we still had a line, and realized it was time to open a permanent shop." Today, the pair run nine boba shops in San Francisco and New York City, and they recently began selling a bottled version that can be delivered right to your office.

5. Eating Green

An environmentally friendly fork made of potato starch is great, unless it bends when you try to spear food. "If you go to a café and it breaks, it's not really any skin off your nose; you'll grab another. But to buy that product for your home? Performance matters--a lot," says Lauren Gropper, who along with co-founders Corey Scholibo and Jordan Silverman spent two years testing resins and molds to launch Los Angeles-based Repurpose, which produces 100 percent compostable, disposable tableware. Gropper says the line--made from corn and reclaimed sugarcane pulp and wood scraps--doesn't "melt in hot soup, warp in ice cream, or snap in half while you're cutting a steak."

6. ClickBait

"Fishermen joke that you always think the lure you don't have is the one that's going to catch the fish," says Ross Gordon, who started Mystery Tackle Box to solve the mythical science of finding the lure that will seduce a particular fish. For $15 to $30 a box, the
Chicago-based subscription e-commerce company--co-founded with Ryan McDonnell and Jason Dirks--sends its customers a surprise mix of lures from an array of brands tailored to their desired prey, from bass to walleye, along with instructional articles and videos.

7. Virtuous Vice

Looking to create a healthy frozen dessert, Justin Woolverton began freezing Greek yogurt and cottage cheese with chocolate and fruit. "I had no intention of ever taking it to market," says the former lawyer. He went with ice cream instead. Five years later, his Los Angeles--based Halo Top Creamery is America's second-best-selling brand of packaged pints of ice cream, according to market research firm IRI. Woolverton says in nearly all the stores that carry his low-cal, high-protein treat--made with stevia, probiotic fiber, and three quarters
of a cup of air per pint--it outpaces Ben & Jerry's and Häagen-Dazs.

8. Getting Schooled

When Michael Fordinal was in seventh grade, his teachers would assign sentence writing for bad behavior. So the budding entrepreneur spent his free time cranking out pages of repentant prose and then selling those sentences to troublemakers for 10¢ a pop. Decades later, he's built another thriving business out of secondhand words--this time, unwanted textbooks. The Irving, Texas-based company hauls away the pallets of books, recycles damaged ones, and resells the rest. "I initially got into flipping books because I had $300 in the bank and $400 worth of bills due," Fordinal says. He discovered that reselling books from local bookshops was profitable but not scalable. "I didn't want to be scanning books and shelves 50 hours a week for the rest of my life," he says. So he started buying directly from schools and booksellers, and today the company processes more than four million pounds of books a year--sorting through 50,000 books in a busy week. "You don't have to have the sexiest idea in the world to run with it," he says.

9. Glass Half Full

The first six shipments of custom-cut glass that CEO Ahmed Mady mailed from his Columbus Ohio-based Fab Glass and Mirror were broken by the time they reached customers. "I was very naive about the whole process." Mady spent the sweltering summer of 2012 in his storage unit experimenting with packaging. "Through trial and error, we developed a very good way to ship a very big piece of glass that also wouldn't take up too much space in the truck," he says. Now, hundreds of shipments go out daily--glass tabletops, shelves shower doors, and mirrors--cut to every size and shape for both consumers and commercial clients."