My 400g display tank got wet in 2004. It has a stainless steel (supposedly) powder coated frame - but the frame has been rusting for the past 12 years. My sump is a TruVu tank that I bought used in 1993.
But at my parents house, in my old bedroom, which is now my Dad's office, is my 60g Tall Glass tank (36x16x30) - which as of this weekend is 35 years old. I siliconed the top plastic molding back on a few years ago.
Dave B