Schedule Direct doesn't grant commercial licenses. I'm checking out tvrage as mentioned above and Rovi right now.
Edit: If this is a commercial project, I recommend contacting Tribune Media Services (click "License our Content" in the footer at Zap2It.com). That was the solution I chose for my company, simply because they were much more prompt in their response than Rovi. The paid listings are XML files.
If all you need is a non-commercial license, SchedulesDirect works very well. If you have questions about their licensing, they encourage you to ask. We started using their listings and then had to change tack because of licensing issues.