I don't have a favorite tube. But after Bicycle Quarterly found thin latex tubes to be measurably faster than butyl, I want to find some...
https://www.renehersecycles.com/bq-tire-test-results/
Keeping in mind the absurd cost, I'm also curious how those super-light plastic (?) Tubolitos perform.
For mountain biking and commuting I use the cheapest regular old 26" tubes. For now, I like the Schwalbe Extralight tubes when I'm more concerned about weight/performance. SV14, for example.