Bhagavad-gita is the instruction given by Krishna, and Srimad-Bhagavatam is the book containing topics exclusively about Krishna and His devotees. These two books are the special nectar of the words of Krishna.
Srimad Bhagavatam 4.4.44,
The Lord is the transcendental form of eternity, cognition and beauty.
Srimad Bhagavatam 1.5.20,
Everyone is seeking Krishna, for He is the Supersoul of all individual souls.
Srimad Bhagavatam 10.9.21,
Srimad Bhagavatam should be heard by the bonafide representative in the Disciplic line.
The spirit soul can be happy only in the association of the supreme living being, the Personality of Godhead, and nowhere else.
Srimad Bhagavatam 3.2.11,
All the universes with innumerable stars and planets are controlled by the intelligence of the Personality of Godhead.
Srimad Bhagavatam 1.1.1,