So about a month ago I hosted a little book club where the topic was children's books. In preparation I asked my family members what some of their favorite books were and here are their replies:

Joel:

St. George and the Dragon!
Where the Wild Things Are
Blueberries for Sal
Tikki Tikki Tembo
Stone Soup
5 Chinese Brothers

Shannon:

Some of my favorite Author/Illustrators are Kevin Henkes (Lilly and the purple plastic purse, Owen, Chester's Way, Wemberly Worried, Julius baby of the World, Jessica, Chrysanthemum, Sheila Rae the Brave), because each book has a flawed character with a very real childhood issue that kids fall in love with (neighborhood bully, a beloved blanket that you don't want to part with, a younger sibling, a fearless and creative friend, a family name that classmates tease you about, an imaginary friend, a various other childhood fears and issues);  Patricia Pollaco (Chicken Sunday, Just Plain Fancy, Babushka's Doll, Thunder Cake) again for rich illustrations and a wonder cross section of American cultures and subtle but meaninful morals in each book; Sandra Boynton (Dogs, Barnyard Dance, Dinosaurs, Opposites, a multitude of board books) because her books are just plain fun and goofy and memorable for young children; Steven Kellogg (How Much is a Million, Library Lil, Best Friends) because of the attention to detail and humor on each page. 

I also love the Frances collection by Russell and Lillian Hoban (Bread and Jam for Frances, Best Friends for Frances, A Birthday for Frances)  They are classics, along with the Mercer Mayor/Maurice Sendak (Where the Wild Things Are, There's a Nightmare in my Closet), Robert McCloskey (Blueberries for Sal, Make Way for Ducklings), Eric Carle (The Very Hungry Caterpillar, The Very Quiet Cricket, The Very Busy Spider, Brown Bear Brown Bear, etc), and William Steig (Sylvester and the Magic Pebble), Rosemary Wells (Max books) and Shell Sylverstein (humorous poetry books). 

I could go on and on, but basically I am a children's book addict, with a weakness for beautiful illustrations, humor, and meaningful and simple morals  and messages. 

Josh:
The Five Chinese Brothers and Tikki Tikki Tembo.  These are my favorites because of our family's longstanding love of all things Asian.  

Heather:
I loved anything Mercer Mayer (Little Critter),
Maurice Sendack (There's a Nightmare in my Closet)
Anything by Steven Kellogg (Pinkerton, and illustrator of a number of others like The Day Jimmy's Boa Ate the Wash),
James Stevenson (Could be Worse)
James Marshall (George and Martha, the Stupids)
Bill Peet (Cowardly Clyde, How Droofus the Dragon Lost his Head)
Arnold Lobel (Frog and Toad, Owl at Home)
Anything illustrated by Quinten Blake (Captain Najork and most Roald Dahl books)
Poetry by Shel Silverstein or Jack Prelutsky
Then there were the weird ones like Barbapapas, The Rainbow Goblins, The Big Orange Splot, Dorrie Witch series
Dad:
I always liked the Five Chinese Brothers (because of the diverse talents to survive) and Billy Goat's Gruff (because the good guys win).  I guess that these are stories, not books, so maybe they don't count.  I liked Louis L'Amour because he had standards, and the heros always overcame the obstacles without cheating or being dishonest.  
Jeremy:
Recently, we've read all the Pippi Longstocking books, Mrs. Piggle Wiggle books, and Winnie the Pooh aloud at dinner.  Our kids also like to read the Magic Treehouse books, Nate the Great, Henry and Mudge, Amelia Bedelia, Miss Rumphius, Richard Scarry (especially Busy Busy World), Officer Buckle and Gloria, The Seven Picky Eaters, The Rainbow Goblins, Harold and the Purple Crayon, The Giving Tree (or anything by Shel Silverstein), Chris Van Allsburg books, The Monster at the End of This Book (old version with Grover), Sylvester and the Magic Pebble, The Blah, Stone Soup, Wizard of Wallaby Wallow, The Awful Aardvarks go to school, The Stupids, Arthur books, Goodnight Gorilla, Where's My Teddy, Blue Hat Green Hat, Five Chinese Brothers, Morris and the Disappearing Bag, What Do You Say Dear, The Incredible Journey of Edward Tulane, Where Oh Where is Kipper's Bear, Owen, and Hooway for Wodney Wat.

In the more cynical column, we have The Happy Hocky Family, Uncle Shelby's ABZ's, The Stinky Cheese Man, and Calvin and Hobbes.
Me:
Everyone covered the ones I had thought of from my childhood. I think you pretty much can't go wrong with Caldecott books.  Joel also found this list: 
http://www.nytimes.com/1997/11/16/books/children-s-books-50-years-of-children-s-books.html
Now, along with the ones I liked from my childhood my kids and I also like books by Mo Willems (Don't Let the Pigeon Drive the Bus, There Is a Bird On your Head), David Shannon, Don and Audrey Wood (King Bidgood's in the Bathtub), and there are a couple by Amy Krouse Rosenthal that are very cute (Little Pea, Little Hoot). 
At the book club I ended up talking about the Five Chinese Brothers. I also mentioned a few others (Tikki Tikki Tembo, St George and the Dragon) and someone pointed out that the books I liked were a little gruesome and violent. Interesting.