CJ peg extensions, Renazco seat, Superplush suspension re-do, extra fuel (mine's a 2-into-1 with Adv tank), Rekluse EXP clutch, Weld86 skid plate (if you're headed for the rough stuff), better windshield.
I could go on and on.
'04 GS Adv- A fond memory
'07 990 Adventure- still bonding...
How hard can it be?
- Jeremy Clarkson