Mr. Jones (my common pleco) is coming up on at least 7 years old. The one I had before him was around 9 when he passed. I had a Bala shark for five. I think my Bronze Cories are coming up on three years now.
My SW tank is still pretty young. Only 4 and half months old. The oldest fish in there is has only been in there for 4 months. Now I did read a story of a pair of mated clown fish that the owner has had for something like 21 or 22 years/