Good question!
I don't have just one. Thinking back, before the days of obsession and GAS, I was very happy with the old Roland RD-600. Then after that it was the fulfilment of a dream to finally get the RD-1000 (about 12 years after they had stopped making them). Mine had belonged to a BBC cameraman in London and for some reason was unplayed and totally mint. I kept that for 16 years.
I enjoyed my original Nord Piano a lot. But times move on and all my experiments with Nord since have led to big disappointment. For gigging musicians they are one of the best choices but for anorak-wearing home hobbyists like me they just don't seem like the right choice.
For a lower price product the Ketron GP1 was insanely good, despite a sub-optimal action. I had two of those (both were bought direct from Ketron in Italy for £599).
The most acoustic like experience was actually the Kawai CS11. In general I have to admit that I just don't really like Kawai digital pianos. I don't like their piano samples and I'm not wild about their much-lauded actions either. However, my CS11 was in a large bay window with space around it and it really did move the air and created a real, organic impression. At higher volumes it was extremely impressive despite having pianos sounds that were not quite my cup of tea. When I moved it into another room against a wall it was completely useless.
I suppose the two I currently have (Studiologic Numa X GT and Yamaha CP88) are my favourites. I've re-bought them both more than once. I think I'm getting close to selling the Numa though. Taking everything into consideration I think the CP88 is better. There's just a rightness to it for me.
