Salmon - poached or roasted. Accompanied with couscous and mixed roasted veg (and a spoonful of pesto). I tend to put in courgettes, peppers and mushrooms.
Chicken wraps - slice chicken breast into bite-sized pieces, fry up with some kind of sauce (harissa is quite good, or chipotle), then put some in the centre of your wrap with lettuce, tomato, whatever - our whole family likes this, as can choose what goes inside (we also have grated cheese, jalapeno peppers, avocado, soured cream)
Greek chicken - pitta bread pocket with chicken breast marinated in greek yoghurt and lemon juice, then fill pocket with chicken, lettuce, tom, tzatziki, cucumber etc.
Prawn stir fry with loads of veg and some noodles.
Chilli
Soups and stews
Tarragon chicken...etc etc
I quite like the Lean in 15 books for these kinds of ideas though - they're super quick and simple (and largely common sense, but sometimes it's good to have someone remind you of options).