Unless you have been specifically instructed to show up earlier, 10 minutes early is fine, never more than 15 minutes.
When you show up earlier than that, you might actually be a disruption to the the people with which you'll be interviewing. Additionally, the recruiter may be spacing candidates so they don't meet in the lobby.
This does not mean that you shouldn't arrive at the location of the interview earlier. Always make sure you leave in plenty of time to get their early, accounting for any traffic issues. If you planned on traffic and there was none, you'll likely get there earlier than the recommended 10 minutes. If that's the case, stay in your car until it gets closer to your scheduled interview time.