Kasumi: Her white ninja outfit with the cherry blossoms on the little front tassel, with her hair down (not in the ponytail or braid looks).
Hitomi: Her gold halter top and pants...though her brown sailor outfit comes to a close second.
Lei Fang: Her yellow chinese haltertop and short-pants combo.
Ein: His "Hardcore" T-shirt with leather jacket and jeans.
Brad: His first costume in DOA4.
Zack: ...I like his Alien costume. ^^
Gen Fu: The Keebler Elf outfit from DOA3!
Eliot: The Red hoody and pants.
Jann Lee: The Bruce Lee "Game of Death" Jumpsuit in DOA4.
Tina: Her blue DWA oufit from DOA 1 (the one with the blue halter top and the shortish pants)
Ayane: Her white version of her normal DOA 1 outfit (Shows up in 2 and 4)
Leon: I guess his metrosexual model costumes?
Bayman: The scuba outfit. ^^
Bass: ...I don't have any.
Lisa/La Meriposa: Her white kitty costume. ^^
Christie: I actually like the "Tequila Sunrise" bathing suit you can give her in DOAX best. ^^()
Helena: Her "Mint Frappe" costume in DOA2 (the bathing suit), though the DOA4 Goddess costume's pretty too.
Hayate: I guess...his...first costume?
Hayabusa: His skintight shirt and pants outfit in DOA3.
Kokoro: Either one of her "clubbing" costumes.
Tengu: ...My eyes...