If it's just the belts, there are:
Rider 1/2
Kuuga - Arcle
Ryuki - V buckle and decks
Faiz & Orga gear/drivers
Den-O belt
There are also the Complete Selection Modification items:
W, Accel and Lost drivers, as well as the T2 Joker and Fang memory
Though not belts, these are considered to be part of the Complete selection line:
Hibiki's Henshin Onsa and disc animals set
Blade's Rouze card archive
Ryuki's Advent card archive
W gaia complete selection memories set 1, 2 & 3
OOO premium medal collection