I love Gamut strings, and while the Pistoys get a lot of (deserved) love, I'm still very fond of Lyons. I've tried a bunch of brands, but I'm currently on my 4th Lyon G (this time in medium, but I've tried light+, medium+, and heavy as well.) They are extremely well made, last a very long time, and have kind of a "new traditional" kind of sound. Compared to Chordas and the low buck gut I've tried, which are about 90% thump, the Lyons have a noticeable increase in midrange character and really sing going up the neck. That said, it still sounds like a gut string! My only warning would be that if you go for a gut D as well, I didn't find the Lyon D to be much of an upgrade over "generic" gut D strings. If you like gut Ds, it's worth it to spend a little extra on the Pistoy, which is like no other string on the market and it matches the Lyon G wonderfully. Good luck!
Gamut Lyon Plain Gut Bass G String
High quality, craft-made gut strings for bass.