Roland G70 (still have it). 13 Years and counting.
Roland G1000. 11 years.
Roland E60. 3 years.
Roland VA-7. 2 years.
Roland E-600. 2 years.
MediaStation X76. 10 years.

I don't remember if it was exactly 10 years ago, but should mention ..
Roland Prelude. 3 years.
Roland GW7. 1 year.

I also had the Korg PA800 (from Tim), was that ten years ago? 1 year.