Hardware Synths and Reaper!

Hey. Do any of you use a synthesiser to record your tracks? Do they sound good enough for stock music?
I have a roland fa-06 and I use Reaper for recording. I would love to hear what Synths you use and how you connect to the computer for the best sound. I heard vsti plugins are better these days but I still don’t own any good sound libraries. Any recomendations?