Again, baleen whales are whales that do not have teeth. Whales such as, the Gray whale, Blue whale, Humpback whale, and Right whale have baleen plates instead of teeth. Because of this, they let in large amounts of water and filter in krill, small crustaceans, worms, plankton, fish, etc. They do this by scooping up water, sand, and desired food, then letting the water and sand out through the small baleen plate gaps; meanwhile the food gets stuck inside.
Gray whales eat bottom-dwelling organisms such as very small crustaceans (shrimp-like), mollusks, worms, etc. Whales, like the Blue whale, eat up to 8,000 pounds of krill a day. Humpback whales eat krill and smaller fish - most significantly schooling fish. They eat schools of fish by creating bubbles that trap the fish inside (bubble nets) and then they lunge to the surface, picking up the fish as they go (see above image). Finally, Right whales eat zooplankton, crustaceans, krill, and the like.
People usually think of the Orca when they thing of a large-fish eating whale, but in reality, Sperm whales have been known to eat large-fish, squid, giant squid, seals, and even... sharks! The average sperm whale eats approximately 2,000 pounds each day.
The Orca is an apex predator, meaning that it has no predator above itself. They search for food in large "packs," much like a group of female lions or pack of wolves. Because of this, they are efficient and effective hunters. They will eat almost anything made of meat; this includes Great Whites!
Beluga whales eat shrimp, cod, and halibut.
Finally, Narwhals, though a large-sized whale, are not as hungry as the Sperm whale or Orca. Like the Beluga whale, they most commonly eat shrimp, cod, halibut, etc.