2003 Fender USA Stratocaster. Owned since new.
Bought when my eldest spawn was born. I originally had the aim of giving it to her for her 18th, and stupidly told her, but she ended up being one hell of a jazz clarinet player.
I didn't want to give her the guitar for her to sell it, so I negotiated with her and ended being fleeced somewhat but I get to keep it. It is the best strat I've ever played, and I've played a lot.
My longest serving bass was a Status I had owned for decades. But it had to go as I started offloading heavier basses. Now I think the one I've owned the longest is only about 3 or 4 years - my Sandberg TT4 Superlight.