Just a few more: the Mario outfit I missed, plus all the furniture items together..
Big Bro's Hat, Big Bro's Mustache, Big Bro's Shirt
The arcade machine (Luigi and Mario in a fighting game. The cabinent plays music, much like the Starman and Fire Bar do..)
All the Mario items! (I crammed them all together for this. Items on the right side are normally against the wall, or closer to it)
It usually looks more like this.
I was thinking of moving the cannon down to the right corner.
Here's the left side of the room! (I used my basement, as it seemed like the biggest room after all the upgrades)