This list only included collected volumes - so no issues of OMG!
(and we have lots) or all the anthologies I pick up are listed here.
Japanese manga are listed by their original names.

A A' (E)
Akira 1-3 (E)
Alice 19th 1 (J)
Angelic Layer 1-2 (J)
Aquarium (E)
Ayashi no Ceres 1-4, 14 (J)
Banana Fish 1-5 (E)
Basara 1-27 (J)
Battle Athletes Daiundoukai 1 (J)
Big O, The 1-5 (J)
Bishoujo Senshi Sailormoon 1-18 (J)
Boku no Chikyuu wo Mamotte 1-21 (J)
Boku wa Tori ni Naritai (Nishi Keiko) (J)
Call Me Princess (E)
Cardcaptor Sakura 1-12 (J)
Cardcaptor Sakura 1-6 (J/E)
Card Captor Sakura 1-5 (E)
Chobits 1-3 (J)
Choujuu Densetsu Gestalt 1-5 (J)
CLAMP Gakuen Tanteidan 1-3 (J)
Clover 1-4 (J)
Clover 1-2 (E)
Cluster 1-2 (CLAMP) (J)
Codename wa Sailor V 1-3 (J)
Combination 1-3 (CLAMP) (J)
Comic Weapon Cyber Comic No. 021 [Gundam F-90, Gunbuster] (J)
Cowboy Bebop 1 (J)
Cowboy Bebop : Shooting Star 1-2 (J)
Dhalia the Vampire (J)
Derayd (CLAMP) (J)
DNA^2 1-5 (J)
Dragon Kishidan - Dragon Knights 1 (J)
E re ga (Nishi Keiko) (J)
FAKE 1-7 (J)
Five Star Stories 1-6, 8-12 (E)
Four Shoujo Stories (E)
Fushigi no Kuni no Miyuki-chan (J)
Fushigi Yuugi 1-18 (J)
Fushigi Yuugi 1-5 (E)
Fuun Sanshimai LIN3 1-3 (J)
Gakuen Tokukei Ducklyon 1-2 (J)
Gouhou Drug 1 (J)
Gravitation 1-2, 6, 10 (J)
Gundam Blue Destiny (E)
Gundam Wing : Episode Zero (J)
Gundam Wing 1-3 (E)
Gundam Wing : Blind Target (J)
Gundam Wing : Blind Target (E)
Gundam Wing : Ground Zero (J)
Gundam Wing : Ground Zero (E)
Gundam Wing : Anthology 1st, 2nd, 4th, 6th (J) ?
Hana Yori Dango 1-30 (J)
Handsome na Kanojou 1-9 (J)
Ho-mu (Home) 1-2 (J)
Imadoki! 1-5 (J)
Juuichi Iru! (J)
Juline 1-2 (E)
Kaikan Phrase 1-17 (J)
Kaitou Saint Tail 1-7 (J)
Kakutou Komusume Juline 1-5 (J)
Kareshi Kanojou no Jijou 1-12 (J)
Kawaisouna Ohimesama (Nishi Keiko) (J)
Kaze to Ki no Uta 1-10 (J)
Kodomo no Omocha 1-10 (J)
Koko wa Greenwood 1-11 (J)
Koko wa Greenwood (aizouban) 1 (J)
Kugatsu - September (Nishi Keiko) (J)
Lodoss Tou Senki : Deelit Monogatari 1-2 (J)
Lost Universe 1 (J)
Love Hina 1-8 (J/E)
Love Song (Nishi Keiko) (J)
Love Song (Nishi Keiko) (E)
Magic Knight Rayearth 1-3 (J)
Magic Knight Rayearth 2 1-3 (J)
Magic Knight Rayearth 1-6 (E)
Magical Pokemon Journey 1-4 (E)
Maho Tsukai Tai! 1 (Dragon) (J)
Majutsushi Orphen 1-2 (J)
Majutsushi Orphen Parody Special (J)
Marmalade Boy 1-8 (J)
MARS 1 (J)
Mimi wo Sumaseba (J)
Mimi wo Sumaseba : Shiawase na Jikan (J)
Miracle Girls 1-9 (J)
Miracle Girls 1-3 (E)
Mizu ga Kooru ni naru Toki (Nishi Keiko) (J)
Mizu no Yakata (Kodacha Bangaihen) (J)
Mou Hitotsu no Umi (Nishi Keiko) (J)
Nadesico 1-2 (E)
Neon Genesis Evangelion 1-5 (E)
New Vampire Miyu 1-5 (E)
20Mensou ni Onegai!! 1-2 (J)
No Need for Tenchi 1-8 (E)
Oh My Goddess! : Adventures of the Mini-Goddesses (E) 
OL Shinkaron 1-5 (J/E)
Outlaw Star 1-3 (J)
Parasyte 1-2 (E)
Peach Girl 1-7 (J)
Peach Girl 1-2 (E)
PiPiPi Pocket Monsters Adventures 1, 3, 5, 7 (J)
Planet Ladder 1 (J)
Pokemon (Toshiro Ono) 1-4 (E)
Princess Knight 1-2 (J/E)
Private Opinion (J)
Quartet Game (J)
Ra-i (J)
Record Of Lodoss War : Lady Of Pharis (E)
Record Of Lodoss War : The Grey Witch 1-3 (E)
Rex (CLAMP) (J)
RG Veda 1-10 (J)
Rurouni Kenshin 1-28 (J)
Rosemary Hotel Akishitsu Ari 1-3 (Nishi Keiko) (J)
Shadow Star 1 (E)
Sailor Moon 1-11 (E)
Sailor Moon SuperS 1-4 (E)
Sailor Moon StarS 1-3 (E)
Saint Tail 1-2 (E)
Sanbanchou Hagiwara-ya no Bijin 1-9 (Nishi Keiko) (J) 
Sayonara Juliet (Nishi Keiko) (J)
Shin Shirayuki Densetsu Pretear 1-4 (J)
Shin Shunkaden (CLAMP) (J)
Shin Vampire Miyu 2-3 (J)
Shirahime Shou (CLAMP) (J)
Short Program (E)
Shoujo Kakumei Utena 1-5, Movie (J)
Slayers : Medieval Mayhem (E)
Sorceror Hunters 1-7 (E)
Spirit of Wonder (E)
Star Wars : The Phantom Menace 2 (E)
Star Wars : The Empire Strikes Back 1-4 (E)
Star Wars : Return of the Jedi 1-4 (E)
Suki Dakara Suki 1-3 (J)
Tenchi Muyo : Tenchi in Love 2 Eternal Memory (J)
Tenkuu no Escaflowne (Hitomi) 1-2 (J)
Tenkuu no Escaflowne 1-8 (J)
Tenshi Kinryouku - Angel Sanctuary 15, 17-20 (J)
Tenshi ni Naranakya (Nishi Keiko) (J)
Tera E 1-3 (J)
Tokumu Sentai Shinesman 1-4, 6-9 (J)
Tokyo Babylon 1-7 (J)
Vampire Miyu 1-2,7 (J)
Vampire Yui 1-5 (J)
Vampire Yui 1 (E)
The Wanderer 3 (J)
Watashi ni Suki na Hito (J)
Watashi no Koto dou omotteru? (Nishi Keiko) (J)
Wish 1-4 (J)
X 1-17 (J)
X/1999 1-6 (E)

MIA (I bought them, but I can't find them!) - 
Five Star Stories 7 (E)
Star Wars : A New Hope 1-4 (E)
Star Wars : The Phantom Menace 1 (E)