It all depends upon what you want to do with your Play book. This is what I would recommend.

1:- Need for speed Undercover
2:- Poynt
3:- Adobe Connect
4:- Gee Reader
5:- Scratch Pad
6:- Wather Eye
7:- Axvoice

Remember, if you don't know how to use these apps, just search the related videos on youtube.