I have loved the Berryz for a long time now, and am VERY happy to see that Itunes has added more of them! Piriritoikou is my fave Berryz song and my second fave is Munasawagi Scarlet, followed up by Yuujo Jyunjou Oh Seisyun. I HIGHLY recomend getting Piriritoikou! It is feel-good, happy song and I love it!
I've been hoping that iTunes would get around to adding Berryz Koubou, and finally they have arrived! Woot! I love this group, and Piri Piri to Ikou! is one of my favorite early songs of theirs. Very fun and catchy! Kacchoee! is also very good.