Fun to read Chinese - Many picture books, read aloud in Chinese, with Chinese characters and sometimes English words on screen. The videos are short, 1-2 minutes. The voice is very 'high-pitched', little-kid-ish, but I guess that fits with the content of the books.
Short Chinese Stories for Kids by MandarinChinese Lessons- These are a series of 100+ short cartoons for kids, narrated in Chinese, with Chinese subtitles (no pin-yin though). The videos are less than 2 minutes long each, but it's hard to know what's going on in the story sometimes.
Kids Chinese Songs by MandarinChinese Lessons - These are cartoon videos of Chinese songs/rhymes with Chinese subtitles, including pin-yin. Each one is less than 2 minutes long.
These are geared for pretty young kids (probably preschool to younger elementary), but I think even my 10 year old and 8 year old are OK with this as an introduction to hearing Chinese and trying to follow along with pictures. It may seem a big babyish, but we're going to use these until they can understand more, then move on to more complex cartoons. I'll post some more complex ones when we move on to those.