Looks like LaunchBox Digital is off to a good start — I just got home from the impressive Palo Alto, Calif. demo day for the first “class” of companies that LaunchBox incubated. The lineup was announced earlier this week, but this was my chance to talk to the founders and try out the products.The Washington, D.C. firm selected nine startups to advise and fund for between $25,000 and $40,000. After three months of work the startups were ready to make their pitches — yesterday in D.C., and today in Silicon Valley.So here’s a ranked list of the five companies that stood out, in descending order. Keep in mind that this is based on first impressions, short demos and whether the concept grabbed me; I didn’t get explore any product in-depth. Still, as I talked to other attendees, the top three in particular seemed like the consensus choice. (Interestingly, they’re also the three companies that TechCrunch selected as its LaunchBox favorites when the lineup was released.)1. JamLegend — This is a free, more social version of the hit video game franchise Guitar Hero. Guitar Hero and the competing game Rock Band offer ways to play online, but JamLegend co-founder Ryan Wilson says those communities are limited. After all, it costs hundreds of dollars to play either game — you need to buy the console, the equipment and the games themselves. JamLegend, on the other hand, costs nothing, and you can play on pretty much any device. After the presentations, I got a chance to rock out using a computer keyboard, and I kicked butt (on easy mode).The site is in private testing, and the song library is limited musicians. But there’s a lot of potential on that end, because Wilson says the site could become a platform for independent musicians to promote themselves, eventually leading to a much wider selection of songs than Guitar Hero’s. Wilson says it’s too early to know whether JamLegend will try for deals with major record labels, but I think those deals will be key — supporting indie bands is nice, but part of Guitar Hero’s appeal is showing your chops on your favorite hits.Here’s a video demo.