I found the Novation gave more immediate 'trance' sounds, but I couldn't make it 'scream'. The Virus is all very nice - the C sounds particularly good, but the user interface is fouled up beyond recognition. In a studio session, I couldn't find a way to manipulate the LFOs on a lovely trance lead patch... Nor could my friend, or the engineer! In the end we had to abandon the sound.Frustrating when you're paying for time, even more when you've found the right sound!
A Nord Modular or Nord Lead would be a good investment, from what I've heard of the sounds they can produce. Really crisp.
For software, if you want that Novation sound, the V-Station is quite lovely. Then back it up with Absynth or D'Cota for interesting pads and atmosphere... And some gorgeous lead & percussive sounds. I've had trouble with D'Cota in Logic though... The release on at least one oscillator seems to be permanently set to infinity!
I really like PlasticZ - a very unusual, deceptively simple soft synth, good for plastic, springy or lead sounds. Perfect for cutting hardcore effects, with some nice effects tucked away. Get a Muon Tau Pro from acid squelches, maybe a Beast for screaming Juno style hooverness (you can get the Juno X for this, and the Beast has a few sound issues - it locks out synths on Cubase SX and kills the sound on Logic for me.)
But more and more I'm using the default synths in Logic 5 Platinum. They have a lovely sound, lots of high end detail in the best possible way, and simple UIs. Maybe just a little generic though.
Oh, and don't forget the Moog Modular V soft synth. It sounds gorgeous for that real analogue feel...
Mmmmmmmmmmmmmmmmmmmmmmm.........
Quite a processor hog though.
Tequila