Thank you for that list. When I played live, I found I needed a piano and an organ, but when recording, I find synthesizers (AN1X, various free weird VSTs, fm synths etc) to be more interesting. In fact I bought a pretty nice piano VST during one of those manic pre Christmas sales and haven't really used it.
For recording, I like the AN1X because it only takes a minute to tweak a patch and with all the different modulation paamaters you can have a constantly evolving sound. Try modulating things with a very slow LFO set to random, with the keyboard set so the LFO doesn't reset when you take your finger off the key.
Jimmy