The ‘best’ local local? No doubt: it’s The Whitchuch Inn: http://www.whitchurchinn.co.uk/ Good honest pub food, steak recommended. Also a drinkers pub with lots of ‘regulars’. You will find yourself at home here.
The Cornish Arms: Great beer. Try the Tribute! http://thecornisharmstavistock.co.uk/
New to Tavy: J.D. Wetherspoons. West Street. Cheap beer and food but heaving.
Just outside Tavy on A386 to Okehampton: The Trout and Tipple: http://www.troutandtipple.co.uk/ Quaint quiet pub, good food and real ales.