Of course you could always go the hardware path as well. You could buy a dedicated synthesiser workstation and some sequencing software (if you can't play the keyboard) and create some pretty good results that way too.
If you go the workstation route it would probably be cheaper and easier to use than the soft synth route. Soft synths give you a lot more options as far as effects, number of tracks you can layer, and very realistic sounding samples in Virtual Instruments. However, if you are not very computer savvy, soft synths can be a pain in the ass with constant computer crashing and the dreaded latency. The more stuff you want to run, the bigger (disc space) and more powerful your computer has to be, thus more expensive. Especially if you are running VI (virtual instruments). There are VI libraries running between $5,000 to $10,000 right now. In my opinion, synthesiser workstations are simpler to use and more cost effective. Then again, it depends on the type of music you want to record as well.
I use the Korg Triton workstation and if you would like to hear some samples of my music go to sonicpsyops.com in the Music section. My style is more New Age/Neoclassical but you'll get an idea of what you can accomplish.
DISCLAIMER- I'm not saying workstations are any better than soft synths, in fact I think, eventually, the soft synth market will surpass worksations even though workstation sales are booming currently. Please, no flame wars from soft synth users. I'm just providing another option for SacredDispair that wasn't mentioned.