Land-a Panda (was $0.99) Land-a Panda HD (was $1.99) Meow Meow Happy Fight (was $1.99) Meow Meow Happy Fight HD (was $2.99) Piyo Blocks 2 (was $0.99) Their other Apps that have been free for a while: Piyo Blocks Off the Leash
Meow Meow Happy Fight is essential; don't let the zaniness keep you from one of the best dual stick shooters on iOS.
^^ Yep, those would be my two picks as well. And Off the Leash is also pretty good (even though it's already freemium).
Add Land-a Panda in as an essential. It's a very good game. Both Piyo Blocks games rock as well. Really, there's no reason not to get all of the free offerings here.