Night Guard

Hi ladies. I had my routine dentist checkup a couple weeks back and my hygentist and dentist both said I need a night guard because I have a bad habit of grinding and clenching my teeth. I asked which ones are good and they said it didn't matter. I've known I few people buy certain ones at the store and they were crap. They aren't cheap so a goid one from the start would be nice. What's a good night guard? Brand? TIA