There is always something new to add, or a modification to make. Here is my wishlist for content and/or accessories.

Train Simulator Content:
Steam Wishlist.
JustTrains.net Wishlist.

Track IR5 (Amazon.co.uk)
TrackIR is a head tracking input device designed for use with gaming and simulation PC titles. It is an infrared camera that tracks the position and orientation of your head, and then sends that data to any of the 100+ TrackIR Enhanced games and simulations.

Foot Switch (Link)
A foot switch that can control safety systems in Train Simulator.

Orby Switch (Yellow) (Link)
An easy to use button to be used with safety systems on locomotives in Train Simulator.

TRRS 3 Way Splitter (Link)
To connect the above switches.

X-keys® USB 3 Switch Interface (Link)
To connect the above switches.