My favorite restaurant with my toddlers was sushi. Quick, delicious, OK to eat as finger food, available in toddler-sized portions.
Otherwise, my criteria for "family friendly" meant:
- Reasonable timelines. I don't want to wait 45 minutes for a table (I'm fine making reservations, but the no-reservations places that make you wait an hour+ in the waiting room ... no thanks), I don't want to sit at the table for 45 minutes waiting to place our order, I don't want the food to take forever. Dinner does not need to be a 2-3 hour event with young kids.
-Kid sized (and -priced) options. Doesn't need to be a kids menu with chicken nuggets and plain pasta. I actually preferred kid-sized portions of 'normal food'. Sometimes an appetizer or side dish makes a good "meal" (often combined with bites from DH's or my plate). Chicken skewer appetizers, side of meatballs + side of broccoli, etc.
-High chairs and changing tables. Bonus points if both the mens and womens restrooms have changing tables!
- General noise and activity level that doesn't make me feel like an a$$ for bringing a toddler in. They were usually well behaved, but a sudden squawk can light up a room with little warning.
- Not necessary, but extra signals that you not just tolerate but actively appreciate families: paper activity placemats with crayons, non-breakable kids cups with lids and straws, training for servers to smile at and engage with kids. And a kids dessert with their meals (cookie or small scoop of ice cream, nothing huge) never hurts

.