My first flight sim was some POS for the Commodore VIC 20. It had gauges and sound, but no views out of the windows.
I then went through every version of MS Flight Sim up to 2000, plus Combat Flight Sim 1,2 and 3, and the Microprose classics F15 Strike Eagle and Apache Gunship 2. M1 Tank Platoon was also a favorite.
Strangely, I never thought of playing on-line. I didn't have internet at home until 2001 and the arrival of DSL. (I always had fast internet at Uni / work and dial up seemed too painful). It was one of the Military Channel ads that got me into AH2 about a year ago.