Knightmare.com

If they'd based the Knightmare theme on the DuckTales theme...
Official recording of full song

Don't watch Tony Hart and Morph
Switch to Dunshelm
Mine-carts, ogres, Smirkenorff
It will overwhelm
Might solve a mystery, while feet get blistery

Dunshelm!
(a - whooh ooh)
Each Friday they're out there having Funshelm
(a - whooh ooh)
Helms to wear when all is said and Dunshelm

An antechamber
(Treguard's resting)
Enter stranger
(Now there's questing)
What to do?
Just tune into some Dunshelm
(a - whooh ooh)
Each Friday they're out there having Funshelm
(a - whooh ooh)
Helms to wear when all is said and Dunshelm
(a-whooh ooh)
Not steersman's helm or soldier's helm, no - Dunshelm!
(a - whooh ooh!)