[quote name='dark_inchworm']Peggle is amazing. I refuse to accept dissent.[/QUOTE]
Agreed. Wonderful casual game that feels like a cross between pinball, pachinko, and pool. Tons of levels which provide a great variety of challenges, plus more stuff to do after you beat the game. The variety of characters and their powers is great too. Oh, and like all PopCap games, the sound effects are perfect and really add a lot to the game. I like Plants vs. Zombies better, but still recommend Peggle in a heartbeat.
As for the Peggle Night DLC, it doubles the length of the game and add (I think) 2 new characters. Certainly a worthwhile purchase if you like the main game.