I can't list just 1 thing - so far, I have spent just over $700 picking up things I have missed over the years (and I haven't worked my way through hair just yet).

Unfortunately, I still have a staggeringly large list of goodies that didn't return.  Things like:

Keiza & Julia for Sydney by 3d-Arena

Daniela for Sydney & Mamoru for G2 Koji by Nouschka & Steve's Art

Blodeuedd for Jessi 2 by Chall-art

Jessi & James (P6) expression bundle by A_

Lolly Dolly for P6 Jessi, Satori & Mari for Miki, Xiulan for Miki 2 by atelier Arie

Shakina for Jessi, Bandida for Miki 2 by geometrya

Character & Texture Pack for Jessi by Hindsightstudios

Janet for Jessi Lores by Idler 168 (along with a number of other items they made, like IA's Outfit for Jessi & Miki, IA's oufit 5 for Miki, Clothing Pack 3 for Miki, Platform sandels for Miki, etc.  Not to mention all of the texture sets made for them by Hitman47.

Linn for Miki & Roxanne for Miki by Freja

the Miki & Koji Expressions Megapack by Jo Le Gecko

Mikido, Royaly & Pussycat for Miki, Nyl, Kessi, Lalha O~Laika for Jessi by LyRainbow

A koji texture set by Elor once Dark (lost the link)

Ik Moon Miki 2 by Ikillerich

Turkish Delight & Inuuseq for M3 by TrekkieGrrrl

I am hoping for another vault release with these items in them.