After using Stan's NoTubes sealant for years we have switched completely to Orange Seal, in our experience there is nothing better on the market.
It is slightly more expensive but better in every other way.
This is the Endurance version, engineered to maximize longevity. Enabling riders to go up to 6 months between refills.
Proven to seal large punctures up to 1/4″ and perform under varying temperatures and altitudes.
26, 27.5, 700c and 29 x 2.25 wheels usually take 4 oz per wheel.
29 x 2.4-2.6 and Plus bikes take 8 oz.
Here is an an in-depth review on SingleTracks.com