Solar Banksticks!
I bought them back in the 1990's and still use them as banksticks, or to make the P1 pod higher. That is also around 10years old.
Shimano 7000 XTA Beastmaster reels, I've got 4 of them, again I think 10years old already. One is on my Spod rod, so is well abused.
They are still selling for the original retail price on Ebay.
If there is one person who uses and abuses gear, it's me.
Other items that have lasted:
100litre DPM Bergen rucksack, it's still alive although I updated to the MTP version last year.
Love them or hate them my Delkim ST's bought around 2000, and still in use for pike fishing.
Shimano Aerlex 8000's still going, used occasionally for pike fishing and if I need both spod and marker rods separately rather than one combined.
Century Big Bertha and her DD's, still spodding, and that must be a turn of the millennium rod!