Well, if you're after virtual analog, definitely try to get a hold of Nord Lead.
Novation SuperNova is really good as well. I personally have the Nova (table top version of the SuperNova). It's a killer and I always take it to gigs. It's got a very fat sound and it's easy to program.
Also, check out Yamaha An1x. They are good, but hard to find nowadays.
Check out Waldorf stuff as well. My friend uses Waldorf "Orange" and he loves it.

-ED-