Although the Spitfire was much more celebrated, it can certainly be argued that the Hurricane was the more important airplane in allowing the Royal Airforce to defeat the Luftwaffe in the Battle of Britain.
The Spitfire usually gets more attention because it was a flashier and more stylish airplane. It was also faster and was made by a company whose planes had won important races while the Hurricane was made by a company more known for making biplanes. Because of these factors, the Spitfire is the airplane that gets most of the credit and publicity for the RAF victory.
However, the Hurricane was arguably more important than the Spitfire. More Hurricanes were produced and used in the battle. Pilots flying Hurricanes shot down more German aircraft all told than pilots flying Spitfires. In that sense, the Hurricane was the "workhorse" of the battle while the Spitfire got all the glory.
Both airplanes (and of course their pilots) were very important, but the Spitfire got the attention. That makes the Hurricane the "unsung hero" of the Battle of Britain.