This is a great package, especially for the uninitiated, but $30 seems a bit steep to me. (After all, a lot of these games, like Osmos, Braid, World of Goo, Cogs, and Crayon Physics Deluxe, have been offered for $2.50 or less during other promotions.)
The two I'd really go for are Machinarium and The Maw; I wish Steam offered some deals on those two.