For me, it's the other way around. I don't know about you, but flight simulators are the one type of program that i've never grown tired of.
I've got many other games that I occasionally play, but after a while, they all get old.
Here's a few of my own suggestions to keep FS exciting.
Find what type of flying you like most and add your own challenges.
Explore new places.
Download new aircraft, scenery, ect to spice FS up
Use RW weather. Always makes for an interesting flight when weather turns sour
One thing I got tired of was turning the autopilot on, coupling it to the GPS, and waiting around while watching the aircraft navigate on it's own. My solution was to simply stop using the GPS, and navigate using nav radios, and charts. Being more involved is more exciting for me
You could also join a VA of some sort
There are many ways to make it fun and exciting, but that's the beauty of it. You make it what you want
