Links to SoundFonts and other similar files
To fully exploit the capabilities of SynthFont you definitely need a good General Midi SoundFont. A GM SoundFont has presets (instruments) defined for all 128 melodic midi programs, plus at least one percussion set. Within this list you will find links both to GM SoundFonts and to SoundFonts with individual instruments.
If you know of a site you think is worth listing here, then please contact me.

For a list of SoundFonts I recommend and offer for direct download, go here.
SoundFonts4u by John Nebauer
John Nebauer has released a Steinway Piano SoundFont from the samples provided by University of Iowa (Samples are Creative Commons Licence) as well as a nice Acoustic Guitar using the samples provided by Keith Smith.
OmegaGMGS2 by Rick Simon
Says Rick Simon: "I made a SoundFont that is General Midi, General Midi 2, Yamaha XG, and Roland GS compatible." ... " I have tried many SoundFonts, commercial and free, and I think it comes in favorably with higher quality samples yet keeping a smaller size for ease of use and quicker downloading.  It is also compatible with virtually every midi song file available. "
Says Marcin Dziembor: "I decided to create my own GM .SF2. Something made out of precisely picked out samples out of every single SF2 file that I will stumble upon."
Prinsess Soft GM SoundFont by Giovannino Imperi
"Princess soft sf2 comes from a selection of the best presets of the web. The realisation of this bank, always updating, has required several months of hard work." Feel free to listen to a demo.
This site does not ONLY have the Merlin SoundFonts but a rather large collection of other free SoundFonts.
Arachno by Maxime Abbey
This bank includes many famous sounds from the best synthesizers by Roland (D-50, Sound Canvas...), Korg (M1, X5...), Yamaha (MU, Clavinova...), Fairlight (CMI), E-MU (Emulator), Ensoniq, and many others.
Giant Soundfont 5.5: Note that you will need to download banks 1, 2, and 3 of v5.5 as well as the drumkit which is labelled v3.0. Giant soundfont is 450 MB uncompressed, the author updates it regularly.
The creative commons-licensed orchestral sample library Sonatina Symphonic Orchestra is a free library by Mattias Westlund in SFZ ("SoundFez") format. Sounds good!
"Here you can download free sound samples, soundfonts, wavs, hip hop samples, etc. for your use in music production and hip hop beat making."
"Original good quality soundbanks, in different formats, mainly harpsichords and pipe organs"
"High quality sound samples for music production and sound effects for the multimedia/movie industry" Various formats
Site by the people behind the Composition Contest site. Get the free Merlin SoundFonts here!
Authentic guitar sounds. Some free SoundFont demos. By Andreas Lundsfryd Jensen
Some free SoundFonts
A classic place to go. Large selection.
GeneralUser GS is a very good GM and GS compatible SoundFont
Some very good orchestral SF's
This is a Swedish FTP server with mostly old stuff.
Soundfont Resources, lots of links.
Rather large list. Site is in Turkish language only.
Well, eh... The Jazz Page.
The Maestro Concert Grand by Mats Helgesson.
Here you will not only find a collection of SoundFonts, but also SoundFont editors, players, and utilities.
... a SoundFont archive since 1995. Here you can find some of the classic GM SoundFonts (in "Banks").
Ethan provides a set of original musical instruments.
Seems to be a large collection?
126 free hip hop soundfonts.
57 random single instrument soundfonts.
"This library is online for ten years and is one of the earliest soundfonts library on the Internet." 32 SoundFonts to download.
Timbres Of Heaven by Don Allen
"Don has worked to perfect this unique soundfont, and has authorized Midkar.com to share it as a Free SF for all MIDI enthusiasts. Timbres Of Heaven is Roland GS compatible. This means that there are many more instruments available than a standard GM set."
"I have made a large soundfont for orchestra with realistic (mostly studio recorded) audio instead of generic MIDI... I then mixed those into the default soundfont, so that my good ones replace what they can, but the old MIDI for the ones I didn't have are still there..."