But there is no BEST ...

But if you liked the GEM back then, i think you might like Korg PA2x nowerdays for its interface...

Its the keyboard arranger that gives you as much sound design options as those old GEM's had..

I can't however tell which ones sound you liek best, thats what you need to find out yourself... So try and find a shop that has most of the TOTL arrangers setup for demonstration and play your heart out till you made your decision.