My top 3:
Machinarium - https://itunes.apple.com/us/app/id459189186?mt=8
Kingdom Rush HD - https://itunes.apple.com/us/app/id489265199?mt=8
Zombies. - https://itunes.apple.com/us/app/id568711604?mt=8
Mini is a monster
Recently downloaded Machinarium, and I agree, it's a great game too!