I wrote a HUGE reply and it got deleted!! Ugh, I will try to replicate. :( I'll list it by author, then a few of our favorites (though most of these authors have lots of others that I also love)
Robert McCloskey - Make Way for Ducklings, Blueberries for Sal
Julia Donaldson - The Gruffalo, Room on the Broom
James Marshall - Miss Nelson is Missing, George and Martha, Space Case
Virginia Lee Burton - Katy and the Big Snow, Mike Mulligan and his Steam Shovel, The Little House, Choo Choo
David Shannon - A Bad Case of Stripes
David Gordon - The Three Little Rigs, Hansel and Diesel, The Ugly Truckling
Rosemary Wells - hers are mostly silly but a lot of fun for the kids to read.
Russell and Lillian Hoban - Arthur's Pen Pal, Arthur's Funny Money, A Bargain for Frances, Bread and Jam for Frances (for the Frances books, make sure you get the full versions and not the ones marked "I Can Read, which cut a lot out)
Arnold Lobel - Frog and Toad, Mouse Soup, Uncle Elephant
Paulette Bourgeoise - Franklin is Messy and other Franklin books
Mercer Mayer - dozens of Little Critter books
Jean Van Leeuwen - Tales of Oliver Pig, Tales of Amanda Pig
Marc Brown - Arthur's Nose and many others (this is the same Arthur that has the series on PBS)
Jonathan London - Froggy books
There are so many more that we love! Hopefully this will get you started. :)