What are the best FREE apps and games to get on an iPhone or iPad?

I'm going on a holiday and as we're going by coach its going to take a while, so i'm looking for the best games on an apple devise that will keep me entertained. Also i as i may put these on my iPad it would be best if they game did not have to be connected to the internet and they need to be free because i don't really want to spend any money. In other words, what are your favourite free games on your apple device?

any help is appreciated.

Injustice
Clash of Clans
Download a book from pdf

Asphalt 6 or 7 your choice these are the best because there are a lot of cars maps and so on plus the graphics are great!

Injustice
Clash of Clans
Infinity blade 1, 2
Uber strike
Assassins creed rearmed
Assassins creed recollection
Frontline commando
Dead trigger
Shadow gun dead zone
Contract killer 1, 2, z, zo
HOPE THIS HELPS!

Pay the 99 cents, the apps are far better.