I highly encourage anybody who hasn't already used the built in sampler to use it. With some high quality samples and a MIDI keyboard, you can do amazing things.
The nice thing about using samples is that you can collect samples from diverse sound sources including samples of popular/expensive equipment.
You can also process your samples with effects to make them sound thicker. Another technique is to mix together 2 different sounds and use the result as a sample.
Hooray for sampling! Have fun.