Copied and revised from another bbs:
Musume and Company:
Singles: all EXCEPT Ai no Tane & Hyokkori Hyotanjima. Only double dip (first-pressing box and "regular" release) I took was "Joshi Kashimashi."
Albums: all, including regular and special editions of "Second Morning." I also got "Best 1" on vinyl, thinking it would be worth something in the future. All the Pucchi Best/Together collections. And the Early Single Box.
Videos: all PV clip DVDs, including Gambacchae/Hey! Mirai! EXCEPT for "Hyokkori Hyotanjima."
Concerts: First Live and Memory Seishun concerts on laserdisc (yes, LASER-DISC). Budokan, Green Live (ecch!), Live Revolution and Love Is Alive on DVD. I quit buying concerts cause it just isn't the same without a live band.
Tanpopo:
Singles: all.
Albums: all (well, both)
Videos: Just that one DVD, I guess
Pucchimoni:
same as Tanpopo, everything.
Minimoni (well, not everything):
Singles: Jankenpyon
Videos: Jankenpyon, Telephone, Hinamatsuri, Genki/Okashi DVDs
Nakazawa:
Singles: "Junjyou Koushinkyoku."
Gocchin:
Singles: Ai no Bakayaro
Albums: Makking Gold 1
Videos: Clips 1 DVD
Ayaya:
only the "Ne~e" first edition CD single.
DVD: First and Second PV clips; Your Song, Watarasebashi, Zutto Suki de Iidesuka.
Mikitty:
"Romantic Ukare Mode" single
MIKI (1) album (first pressing box)
All PV DVDs.
Shuffles:
CD: The one with Salt 5, 11 Water, 20 Dirt or whatever. The one that had the awesome hardcover book.
H.P. All Stars. HAD to get that one.
DVD: All the DVD releases.
Sakuragumi/Otomegumi:
all CDs/DVDs.
Ancillary CD/DVDs:
Morning Cop (also purchased the VHS)
Pinch Runner: both the movie and making-of DVDs
The Pucchimobics
All the "Idol wo Sagase" volumes
Hello Project Live 2002.
"Hajimete no Happy Birthday" CD -- Country Rika.
"Jinsei ga mou Hajimatteru" CD -- Cubic Cross.
"Folk Days" concert DVD with Sayaka and Yuko. One of the great underrated videos related to Hello Project.
Boo Takagi Hawaiian Medley DVD. A gift.
"22sai no Watashi" -- CD and DVD.
Takahashi Ai Alo-Hello DVD
2001 Fan Club CD singles -- bought via auction and includes my number-one favorite H!P-related song, Rikaishite! Onnanoko.
2003 Sweet Morning Box -- a gift.
Shashinshuu:
MM:
First one (with gen-1 as fresh-faced idols)
Second one (the red cover)
Hamilton Island
Chain! Chain! Chain!
5th Anniversary Photo Book (the Up To Boy release)
Rika:
First one ("Rika Ishikawa")
Second one ("Ishikawa Rika Shashinshuu")
Last one ("hana-bi")
Other solo:
Nacchi 1st ("Nacchi")
Marippe 1st ("yaguchi")
Sayaka 1st ("self")
Konkon 1st
Aichan Alo-Hello
H!P Kids:
nothing
Berryz Kids:
nothing
What else? Various trading cards, a few official photos/stickers (from H!P stores in Harajuku and here in Hawaii), a few Musume pencils (I have an Aibon pencil at work), a Mikitty keitai strap, and every official Musume calendar since 1999.