I only read the first book, these pandas simply ate too often, so I was discouraged from reading more books

Well,

When I read the firts book i thouhgt that "Bamboo Kingodm" is the worst Erin Hunter's book.

But I read the second, becouse i bought two. And I never regretted this. River od Secrets is definitly my favourite book. Now i love this book series, and I want to buy "The Dark Sun"

I'd have to say that Creatures of the Flood is my favorite, River of Secrets is my least favorite, and Journey to the Dragon Mountain and The Dark Sun are tied (they're both pretty mediocre, in my opinion. I'm just trying to finish the series, dunno if I'll bother with the second arc).