What is normally your registered item?

[Scarabi]

I always have the bike equipped; I like to go fast in the games and I have no patience whatsoever for my character to walk or run XD

 

[Gera-Kun]

Bike for when i'm hatching eggs or Vs Seeker when i'm training my pokemon

 

[Satoren]

The key assignment for me changes with each generation.

Gen 2- It was usually the bike, and when near a stream, a Rod of some sort
Gen 3- In my first playthrough, I registered the Item Finder, since for me,the running shoes' speed was competent. with FR/LG though, I almost always registered the VS Seeker.
Gen 4- last I played I spent most of my time in the underground attempting to get rare items. So Explorer Kit wins for now.

 

[Rhyperior117]

For me it is mostly the bike(def when trying to hatch eggs) or the Pokeradar. Every once in a while i would put the vs seeker if i was training my pokemon.

 

[arceus03]

Before the Bike, the Town Map. Then the Bike. Sometimes also Vs Seeker or Rod, in FRLG or any of the older versions I registered Itemfinder for easy use too. And now they've made it a Poketch app, it's very convenient, because not also you don't need to rummage through your bag to find it, also because it pinpoints the exact locations of the items.

 

[ZenixX]

My registered item is always the bike, but on occasions i'll have Explorer Kit or Super Rod registered.