The most fitting objects of Refuge(and protection) are the Three Jewels. Here's why, as Pabongka Rinpoche explains it in the Lamrim(p.357). The four reasons, according to Pabongka Rinpoche, are the 4 unequalled qualities of the jewel of Buddha.
The first reason is that the Buddha is beyond all danger. He has freed himself from all danger as he has no more negative karma or imprints of such karma to be exhausted. Hence, no matter how Devadatta(his cousin and 'sworn enemy') tried to harm or kill him, he was always unsuccessful. Since the Buddha has freed himself from all danger, he is in the best position to help free all sentient beings from danger, directly and indirectly.
The second reason is that "he is skilled in the means to free others from danger". Proof of this is in his ability to subdue Angulimala (who had been consumed by great hostility and had killed 999 people ) and free him from the potential danger of going to the Hell Realm.
The third reason is that the Buddha "reacts compassionately to all, without feelings of intimacy or distance". Hence, by the strength of this virtue, he was able to free Devadatta from illness by swearing that he loved Devadatta(his 'sworn enemy' ) and Rahula, his only son, equally.
The fourth reason is that the Buddha "works for the sake of all others, whether they have helped him or not". Hence he once nursed and cleaned up a sick monk(whom he happened to encounter on a visit to a monastery), who had been left to wallow in his own faeces and urine.
Thus the Buddha loves all beings equally, like a father loves his only child, and works for the sake of all beings, whether they have helped him or not. How then can anyone not have full faith and trust in the protection of the Buddha and the Three Jewels, and take refuge in them?