That's a tough call.....the JVM OD1 Orange gets pretty close and the 5150III (with the right tubes and cab) gets really close. To me, the 5150 III can get closer to the 1984 tone and the JVM gets closer to the VH1 tone.......
But if you really want the real deal.....Mark Abrahamian's plexi build (I think he is "rockstah"?? at the metroamp forum) is the amp that totally nails that old VH tone dead on.......and I mean dead on!!!!