Asking yourself what and who Allah (SWT) loves most is a sign of sincere love towards the Almighty. 
It shows you’re aware of your actions and want to work on your character to please Allah Subhanahu wa Ta’ala. It also displays your desire to get closer to your Creator and strengthen your connection with Him.
Indeed, Allah (SWT) loves those who strive to become better Muslims every day. That said, here are five qualities of a believer loved by the Almighty, as mentioned in the Holy Qur’an:

1- Repentance and Purification
“Indeed, Allah loves those who are constantly repentant and loves those who purify themselves.” 
– Al-Baqarah: 222

2- Incorruptibility
“And if two factions among the believers should fight, then make settlement between the two. But if one of them oppresses the other, then fight against the one that oppresses until it returns to the ordinance of Allah. And if it returns, then make settlement between them in justice and act justly. Indeed, Allah loves those who act justly.”
– Al-Hujurat: 9

3- God-Fearing
“But yes, whoever fulfills his commitment and fears Allah - then indeed, Allah loves those who fear Him.”
– Al-Imran: 76

4- Righteousness
“And hasten to forgiveness from your Lord and a garden [i.e., Paradise] as wide as the heavens and earth, prepared for the righteous who spend [in the cause of Allah] during ease and hardship and who restrain anger and who pardon the people - and Allah loves the doers of good.”
– Al-Imran: 133-134

5- Steadfastness
“And how many a prophet [fought in battle and] with him fought many religious scholars. But they never lost assurance due to what afflicted them in the cause of Allah, nor did they weaken or submit. And Allah loves the steadfast.”
– Al-Imran: 146

May we get the chance to be placed among those loved by Allah (SWT) and reserve the highest rank in Jannah. Ameen.