I don't use synths at all anymore; when I did, I stuck to a Roland JP-8000 and a Yamaha TX-802.
My main soundpath is an Epiphone 12-string acoustic with a Dean Markley pickup (or a Fender Telecaster), fed into a Digitech XP-100 whammy/wah pedal, a DOD distortion pedal, a DOD digital delay pedal, and into a Yamaha SU-200 sampler (sometimes through a crappy little Crate amp and a cheap microphone, but usually directl). After sampling a few phrases and sounds, I play them as overlapping loops in the SU-200, and into a DOD D12 sampler. After creating a few loops in the D12 this way, I play them in unison through a Microverb IV, then back into the SU-200 for sampling. After a few rounds of this, re-processing the same original sounds, I've got quite a dense little drone. Playing this back through the Microverb, at various frequency cut-offs, I can get some pretty deeeeep sounds, very organic sounding, no synth involved. Fun!
I don't use software at all (I've played around with ACID, but prefer a more hands-on approach). I don't use sequencers, MIDI, or any of the traditional electronic music tools; I prefer the random nature of out-of-phase loops and the harmonics of real strings, no matter how blurred by effects they may be. Different strokes, I guess!