Quad-Core Processor Android tablet

i am looking for a Quad-Core Processor Android tablet use for entertainment,studing,traveling.there are three tablet i liked,but i have no idea to choose them.

Yuandao N90FHDRK
http://www.amazon.com/gp/product/B00CG2RI0A/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B00CG2RI0A&linkCode=as2&tag=christengifts-20

Yuandao N80RK
http://www.amazon.com/gp/product/B00CG5MF1O/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B00CG5MF1O&linkCode=as2&tag=christengifts-20

Yuandao N70HD
http://www.amazon.com/gp/product/B00CGDSR36/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B00CGDSR36&linkCode=as2&tag=christengifts-20

Would you please give me some advice?Which one is the best for me?And you can recommend another one if anything else best Andoid tablet.