Here's some restaurants I'm familiar with and would recommend in Livermore:
Mexican - Near Downtown Livermore -
Casa Orozco on L St.
Steak - I580 @ Airport -
Cattleman's
Italian - Downtown Livermore - Bruno's Italian Cuisine (2133 First St.)
Coffee - Downtown Livermore - Panama Bay Coffee (2115 1st St.)
For lunch, I'm partial to a Polish w/Sauerkraut and soda at Costco (I580 @ Airport) for $1.50.