What are the best synth apps/plugins?

[Dash]

Hi, just to start this off.. I have little training in the ways of Synth plugins or apps. However what I do know is that I have Cubase SX3, A Presonus Firepod and a pretty regular keyboard. I have been using the presets for synth on Cubase however only one of them is any worth. It is called Embracer.

Anyways I am recording a demo and am looking for a synth app or plugin that has a lot of effects on it. Secondly like anyone I am looking for the best sounding package(s) out there, which I assume are normal packages or orchestral ones.

So I have come to you for help. Is there anyone out there that knows what the best plugins or apps are (they have to be compatible with Cubase)? For example I downloaded something called Xpand! and it only works with Protools. I did try to find Garritan Personal Orchestra but was unsucessful.

Thankyou!

[mutant!]

if you don't mind spending money, i'm very much in favour of reason for this kind of thing as it has an epic selection of sounds, and a pretty thorough orchestral sample bank.

also, native instruments make some rad vst instruments, but you'll have to decide what sounds you want and then get those packages.

what kinds of sounds are you looking for? vintage synth sounds? rhodes/wurlitzer? piano? organs? orchestral?