I second the apples and peanut butter; I always crave that during pg

hard boiled eggs
nuts, dried fruit (craved dried cherries last time)
Maybe make up some burritos (some breakfast-y with eggs, some with beans, what have you) and freeze them, then when hungry you can just pull one out and microwave it for a quick snack or meal.
I doubt the ingredients are the best, but I saw an advertisement for ensure drinks made for pg mamas.
Ohhh, of course, that made me remember
smoothies. Yum. Milk or yogurt or fruit juice, some frozen or fresh fruit, some extras like wheat germ or oatmeal, ice (unless your fruit is frozen then you might not need it), what ever sounds good, blend, drink. Tofu. Brainstorming here. Maybe gelatin, plain or a flavored kind (tough to find healthy ones without all the dyes and other chemicals).
HTH and I'll be looking forward to other posts for inspiration!
ETA: There is also 'apple pie in a glass', mix applesauce in with milk(... I think.... I'll look it up later and repost if I'm wrong) and add cinnamon (not too much as it is a uterine toner=possible contractions).
I also make up a pie plate of bread pudding (lots of protein and dried fruit) when I'm pg and have a slice, heated or not, when I'm starving.