My vote for the best synth goes to the Yamaha S90. I love the heavy feel and the sounds are awesome to me. I'm not big into creating huge scores or tweaking sounds. I'm not into sampling. I'm just into playing music. I love the pianos, and ep's. I also use a few square waves. Nearly evertime I give this board 30-40 mins, I have a new song ready started. I love it.

My second choice might be the Roland XP-80. I do like the JV/XP sounds.