i use the following decks in my TCG games, any changes i make will be posted here so refer to them for my decklists. i keep my extra deck in a entirely separate pile the following are my extra deck cards that i use as fillers since i don't play in a tourny you are allowed to use a extra deck that is over 15 cards.
Xyz monsters
number 10 illumiknight
number 39 utopia
number 17 leviathan dragon
grenosaurus 2x
syncros
ally of justice catastor
brionac , dragon of the ice barrier
magical android
thought ruler archfiend
colossal fighter
x-saber urbellum
black rose dragon
black winged dragon 2x
shooting star dragon
stardust dragon 2x
majestic star dragon
red nova dragon
red dragon archfiend 2x
ancient fairy dragon 2x
flamvell uruquizas 2x
formula synchron
mist wurm