What do you consider the most valuable upgrade in your TC?

I haven't done many, but here are my mods so far: (Pick one, I like them all)

1. Shower curtain rod extender
2. Oxygenics Shower Head (Wow, I love taking a shower with this option)
3. Torklift Glow Steps
4. Torklift Glow Guide
5. Converted hanging closet to wire shelves
6. Moved the hidden 12 volt disconnect switch so it is accessible
7. Rear Awning
8. Added 2nd step to single step for getting into cab-over area
9. Removed flimsy TV swing arm and replaced with a stronger swing arm
10. Added custom Stainless Steel wind deflector
11. Modified latch on pass-thru window for easier opening and closing while in motion
12. Built and added drawer underneath dinette seat that was just an open storage space
13. Added screen door push bar for easier closing
14. Moved TP holder to a more convenient location
15. Modified floor cover underneath bathroom sink to create additional storage
16. Changed bathroom sink counter-top to Corian
17. Replaced bathroom sink two knob fixture with single handle fixture

Modification in progress:

18. Convert dinette to sofa bed