Just noticed that I dont think these guys have been mentioned yet:
Krakli Synths- Simply astounding how many free synths are here (dont forget the archived ones!)
Odo synths
B. Serrano synths -particularly Adonis (awesome)
HG fortune-STS 26 is just insane.
And finally, prolly my most favorite:
NOVAkill synths-
Numerous and POWERFUL.