I like Sweet Earth's Big Sur Breakfast burrito. I eat it any time of the day or night. Just defrost in the microwave for about one minute, then pan fry in your favorite oil until browned on both sides, and enjoy with Sriracha (my personal preference) or salsa or just on its own.
I know you don't mean things like Boca burgers that require meal planning or toppings, so I'll suggest Daiya vegan pizzas or Amy's frozen dinners. Daiya pizzas take less than 20 minutes to cook directly on your oven rack and are 100 percent vegan, they are kind of expensive, but if cost isn't your concern, they're quite tasty on occasion. They actually make vegan pepperoni (vegan pepperoni!) ...Amy's meals you're going to have to sort through, some are vegetarian and some are vegan. They're known for their dairy ingredients, but never add eggs or meat or gelatin. So anything they make non-dairy is vegan. They have a variety of frozen meals from Indian-inspired to pasta bowls.
Annie Chun makes shelf-stable Asian-inspired dishes like Kung Pao noodles and Pad Thai which are vegan. I used to eat them a lot when I lived in L.A. but I feel kind of guilty about the packaging they use. They taste really good though.