I know it is not easy to ask ( what is the best ... ) however I am looking for the most effiecient stove (ounce for ounce, or pound for pound) among stationary stioves and portable ones.

In stationary stoves ( to be used at home when stay-in-place scenario) what is the stove that gives most calories ( or BTU's) per ounce of fuel ??? In portable stoves ( which can be used in bug out scenarios) what is the stove that will give maximum heat BTU's per ounce of fuel AND stove ?