I've never been too fond of FluidR3. While it has some good sounds, like many other soundfonts it just sounds kinda unbalanced to me, both in terms of volume differences and quality of the instruments. I always liked SGM-V2.01 for old games and General MIDI playback, maybe check that one out. Also, the Crisis Soundfont which has some VERY high quality sounds, but many of them aren't really suitable for live playback so I took the best sounds from there, adjusted them a little and replaced some instruments in the SGM. I eventually added lots of instruments from other soundfonts too.
I do recommend it to anyone to assemble their own personal soundfont, based on your favorite free soundfonts that are floating around and what games you want to play with them. It's fun and you end up with something unique that sounds great to your ears.