I'll echo what has been said and hopefully expand it a bit.

The GM General Midi stuff is the sounds in many of the sound cards.... kind of a base line default set of sounds. These sound pretty cheesy for what we do.

Next up is the inexpensive synths like TTS and Coyote. To my ears, there not a big difference between them, but they do sound a bit better than the GM set.

Moving up again you get into the low priced stuff like GPO. Up to perhaps a few hundred dollars. There's a definite improvement over TTS and Coyote but a close listen on good speakers and you can still hear the "midi" aspect to many of the patches and samples.

Moving up again (IMHO) to the low end professional synths..... this is where Kontakt and the other offerings from Native Instruments comes into play. You also find East/West in this group. These synths are high end patches and good quality samples. With them, you can do professional level work. Orchestral compositions, when properly done, are hard to differentiate whether it is sampled or live. They fall into the several hundred dollars each, up to just under a thousand dollars, range.

Now.... yes, there is still a bunch of higher end sampled synths that you can buy but doing so depends on your discretionary budget. Many of these start with 4 figures and go up. It's kind of rare to find these in the hobby/bedroom studio's tool rack due to their price.

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