this question and way of thinking is just going to lead you into a cookie cutter, boring ass sound if you follow the motif/triton/fantom route.
explore, download demos, find your own sound. you're already boxing yourself in...
go read the different reviews here:
KVR: Virtual Instruments, Virtual Effects, VST Plugins, Audio Units (AU), DirectX (DX), Universal Binary Compatibility - Audio Plugin News, Reviews and Community
there are tons of great synths out now that have excellent sound quality.
shit, maybe you'll stumble on something and people will be asking "damn how do you get his sound?"...