VITAL vst, is an fm synth, it is particularly good in creating that real psytrance bass and kick, but also loads of other sounds can be made with it, there are also a lot of tutorials on this synth on youtube, so you can get accustumed to the synthesis of this synth.
this is a video on this synth, and when you listen to the sounds in it you will understand that for modern psytrance sound with a freeware setup, this is one of the best to get
greetz Frank