TechCrunch’s Picks: The 10 Best Startups From Y Combinator Demo Day

65 startups showed off today at Y Combinator’s Demo Day, and we covered all 39 that were ready for the public. After talking to VCs and tech moguls, the TechCrunch teamed huddled up and picked these 10 companies as the best. They’re disrupting commerce, evolving how we communicate, and making our phones even more powerful.

Check out our coverage of session one, two, three, four, and five to choose your own favorites, but here’s a cheat sheet to the startups we think are going to remodel big industries [change the world], or at least make a ton of money.

Carsabi:  An evolved search engine for buying used cars. Carsabi aggressively crawls every online car sale listing it can find, from classifieds to dealers. It already surfaces more deals than industry leader AutoTrader, and has features that let you sort by the biggest savings, not just lowest price. Social features let users ask friends for purchase advice, which cleverly doubles as a viral mechanism. It’s a huge market, as last year $650 billion was spent on car sales and $3.8 billion on auto ads. Carsabi has 10% week-on-week growth since its mid-February launch, because when people save they tell their friends.

Pair : A private social network for couples first covered by TechCrunch last week, Pair lets two people create a private timeline where they share photos, videos, sketches, activities and more. The iPhone app, which launched just four days ago, has already garnered more than 50,000 registered users who have used Pair to send more than 1 million messages. Pair has received funding from SV Angel and Path founder Dave Morin, who told Pair’s team that Facebook has created social networking’s “cities,” Path is building its “houses,” and Pair is like its “bedroom.” I think the the one-click “Thinking of you” button could be a big hit with guys.

Priceonomics: An online price guide for anything. Type in anything you want to own and it will tell you how much it should cost, like a Kelly Blue Book for smartphones, laptops, TVs, stereos, etc. Priceonomics crawls through hundreds of millions of transactions to find out what people are selling and how much they’re selling it for. It got 250,000 page views in March, plans to make money through targeted advertising, and already has funding from SV Angel, Andreessen Horowitz, CrunchFund, and several angels.

Your Mechanic: Aiming to be the “Airbnb of car repair,” Your Mechanic is a website that connects you with the best mechanics in your local community, and commission them to come to your house and fix your car. According to the company, this is on average 30 percent cheaper than the typical mechanic or car dealership. In private beta, Your Mechanic has had $90,000 in billings thus far, saving each user an average of $200 per transaction.

Sonalight: Touting itself as “Siri on steroids,” Sonalight is an app aimed at letting you send text messages while driving by using just your voice. The app purportedly works even while a phone is your pocket. Already, the app has been used to send 500,000 text messages at a rate of 50,000 per week since its debut back in October. In the long term, the Sonalight team aims to bring its voice command functionality to other devices such as thermostats.

42Floors: Aiming to be the Trulia for commercial real estate, 42Floors has built a slick website for companies searching for office space. 42Floors has also built a marketplace for service providers such as interior designers and furniture suppliers for when commercial tenants need to outfit their new offices. 42Floors already has 10 investors including SV Angel and Startfund.

Exec: Ever wish you had your own personal assistant? The Exec app lets you have one at your disposal within ten minutes for $25 an hour. You can use Exec to outsource errands and small jobs such as dry cleaning pickup and basic research tasks, and so far it has proved quite popular: 99 percent of customers in the past week have rated jobs completed with Exec with four or five stars, 29 percent of customers come back within the first week of using it, and the company has already processed $32,000 worth of transactions since launching in beta earlier this year. You can read our previous coverage of Exec here and here.

Midnox: They’ve built the Luma, an iPhone app that stabilizes the videos taken with a mobile phone in real time. The app also adds full resolution visual filters in real time, which are “non-disruptive,” meaning that they can be changed or removed after recording is over. The company has also built editing tools and sharing features for the videos taken with Luma.

Crowdtilt: A  simple way for anyone to crowdfund anything. While Kickstarter is great for bigger organizations and startups, Crowdtilt is optimized for groups of friends. It specializes in making sure organizers get their money, and in the six weeks since launch it’s seen $400,000 come through its system. That figure is growing at 21% week over week, and 34% of users come back and fund another project. Imagine the fun trips you could go on and parties you could plan when you split the cost with friends.

iCracked: Chances are, if you’ve owned an iPhone, iPod, or iPad, you’ve either cracked your screen at some point or come perilously close to doing so. iCracked has built a very booming business fixing those problems. iCracked says it is currently the nation’s largest iOS device repair company, and it has more than 500 technicians worldwide who can come to you and repair your cracked or water damaged device in a half hour for half the price of its competitors. The company has had over 10,000 customers in the past three months, tripling in size since January, and is signing up 10 new iTechs (device repair people) per week. Going forward, iCracked is looking to expand out of iOS, build an insurance arm, and launch device redistribution models.

Additional blogging by Eric Eldon and Colleen Taylor

Read more Y Combinator Demo Day coverage and check out all 39 startups who presented publicly: