For some reason it's exceptionally hard to post a whole slew of pictures, so the rest of the list will sadly have to be in written form:
The Giving Tree - Shel Silverstein, A classic. Everyone should own a copy of this.
Cloudy With A Chance of Meatballs - Judi Barret, Still the most delightful first time read that I can remember.
Slyvester and the Magic Pebble - William Steig, What really happens when you mess with magic.
BAAA - David Macaulay, This book, while for children, may surprise any adult with its content. Part fable, part political observation, part satire reminiscent of Soylent Green, this is my biggest recommendation on the list.
Tuesday - David Wiesner
Sector 7 - David Wiesner, clearly I'm a big fan of his illustrations.
Many Moons - James Thurber, yes he wrote children's stories too! Spoiled princess wants the moon! What is the court to do?
The Eleventh Hour - Graeme Base, my favorite illustrated mystery/puzzle book. Check out his other stuff too.
Amelia Bedlia - Peggy Parish, I was delighted by these as a kid.
Nate the Great - Majorie Weinman Sharmat. The boy dectective and his love for pancakes. Do you remember these?
I know there are more, so remind me of what I missed!