My favourite picture books when I was little were Jillian Jiggs (we had the one where she was messy and the one with the pigs - I still don't know how the messy one ended because our copy as I remember it has always been missing the last couple of pages!). I also really liked Possum Magic, Sebastian (a book about hand rearing a baby wombat it is soooooo cute!) and I liked random fairytale books and disney stories. Although I never had the books (until quite recently!) I really liked the hairy maclariy series and the book Wilfren Gordon Mcdonald Partridge by Mem fox. Like catlover I also loved anything with animals and quite often I'd get out animal identification books out from the library and whilst I didn't read a lot of them my sister and I loved looking at the pictures and I know with books identifying shells and butterflies (they tend to show a lot of different types on each page) we would go through and pick our favourite one from each grouping. Oh we also have a MASSIVE (as in giant size, like the kind they have at libraries or schools to read in class so everyone can see the words and the pictures) copy of a Brambley Hedge book that shows all the homes and where everyone lives. It was more of a companion guide to Brambley Hedge because it didn't really tell a story but I loved the illustrations of the mice in all their little rooms! Oh and Spot! and Narnia. Oh and I had two golden glow in the dark books, one was called spooky house and one was called stars moons and clouds and I had a bannanas in pyjamas book I really liked (the illustrations are so cute!) and I had some serendipity books I enjoyed (we never had the one with the flying horse, I wanted that one so bad!). Cat Balloon, I liked that (where is that.... I don't remember seeing at my sisters.... hmmm....) Pretty much all of my childhood picture books are at my sisters for her kids so I'll have to go and look at them and then post more 'oh and oh'!
As for actual word books I had a big collection of R.L Stine and Babysitters Club. Enid Blyton - not the secret seven or the books that were more like a series but the more sort of random books filled with different short stories. I read so many YA and childrens books now that I'm finding it difficult to remember what I liked when I was really a kid and I've started to like since then! I did used to like those Animal Ark books and also I liked random books of animal stories (quite often made by Scholastic) with titles like 5 dog stories that were supposed to be true stories of amazing things animals had done.
Childrens/YA books I've liked as I've gotten older are 'Time Stops for no Mouse' and the next one in the series 'Sands of Time', Harry Potter series, Artemis Fowl series (though not the last book time paradox, I thought that was sucky), Graeme Base books (if you like ones with secrets pictures these are awesome!) The Golden Compass books (actually called His Dark Materials Trilogy but most people know the golden compass) The Rats of Nimh is quite good, as is the tale of Desperaux and I really like The Amazing Maurice and his educated Rodents by Terry Pratchett as well as his books about Tiffany Aching. I did like the Darren Shan vampire books until the end and the same with the vampire series by Christopher Pike. By Melina Marchetta I like Saving Francesca and Looking for Alibrandi, and I think I like on the Jellicoe road but I'll have to read it again because I didn't really get some of it! I also really really used to like the 'Tomorrow' series by John Marsden and then he wrote the 'Ellie Chronicles' and there's some stuff in the Ellie chronicles that has made me look at the writer and therefore the books in a bad light. I now have all the Brambley Hedge books and I still love the pictures. Peter Pan - I never read the book 'til I was older and it's a really nice story. The Sheep Pig/Ace are pretty good as is Martins Mice.
I know a fair amount of what I've said is on the cusp of YA/adult but it was intended for children. It's good that more adults are reading YA books because a lot of them can be enjoyed by adults. From Richard Adams I have read and liked Watership Down, Tales from Watership Down, Plauge Dogs and Shardik but I'm not sure if they're meant to be YA or adult. Shardik I think is meant for adults (it's for some pretty extreme stuff in there) and I also really liked the book Tender Morsels that is marketed as adult or YA depending on the country and is a pretty full on adaptation of the story of Snow white and Rose Red.
I like a lot of books!