If we're talking currently played (on again off again in my case) I'd have to say my SWTOR main Aidyn Akash. Â I brought him over from a table top game where my friends and I continued our storyline so I guess that's around ten years.
Of all my characters, I'd have to say A'kos' mentor Xzenivar.  Who originated on a persistent server for Neverwinter Nights, was played in various forms throughout the years including being my main through FF14 1.0 and is a major player in A'kos' backstory and who is actually still alive.  That's uhm,  15 years?
Of all my characters, I'd have to say A'kos' mentor Xzenivar.  Who originated on a persistent server for Neverwinter Nights, was played in various forms throughout the years including being my main through FF14 1.0 and is a major player in A'kos' backstory and who is actually still alive.  That's uhm,  15 years?