+1 for FB
Very happy with the iPad, but if I was going to buy an Android equivalent it would be the Nexus rather than the Kindle. The Kindle is designed for consumption of Amazon content (books, films, music etc) whilst running Android, whereas the Nexus range are much more of an Android device that can also be used to consume Amazon content (as well as other vendors).
We have the iPad 2 and also iPad mini - the Mini is more portable and doesn't seem compromised by the smaller screen. So I'd expect the same to apply for the Nexus 7 and 10; if you expect to only use it in and around the house then the 10 is a bit nicer, but if you will be taking it out and about then the 7 may be a better choice.