Both Dune and Dune II were released in 1992, Dune was interactive adventure from Cryo, Dune II was RTS from Westwood. Dune II was also re-released as Dune 2000 for Windows.
Dune was not bad, but personally I love Dune II a lot. It was the first RTS I played, and it had such a huge influence on this genre for the years to come.