If I had to pick one of the Buddha’s disciples who I admire the most, it would be Venerable Sariputta. He was the disciple most highly praised by the Buddha (AN 1.187) and foremost in wisdom (AN 1.189). He was a supremely skilled meditator (AN 7.41). He taught about profound Dhamma subjects like dependent origination (MN 9). He could easily expand on the Buddha’s brief statements (MN 114). He gave practical strategies for dealing with the hindrances encountered in daily life (AN 5.162). He had loving-kindness and compassionate for others (SN 35.87). He really was the complete package, the real deal.
EDIT: To add the sutta Venerable Sariputta’s Lion’s Roar (AN 9.11) where he proclaims his great qualities.
Well maybe one of them would be Mahākassapa not because he’s a tough guy, but for his simplicity, contentment and integrity (SN 16.1, SN 16.3 & SN 16.4).
His verses in the theragāthā about being weary of adulation and delighting in rocky crags always make me smile and remind me of why I ordained. Also being able to stay calm when someone’s finger drops off into your alms bowl is impressive. Sakka, lord of the gods, went undercover in order to offer him alms (Ud 3.7) and the Buddha swapped robes with him (SN 16.11).
But the story about them I love most is when Nakula’s Father is about to die, and his wife comforts him by explaining that he need not worry about her when he dies, for she is perfectly able to look after herself, both in material and spiritual ways.
And in order to make sure that she really means what she says, she tells her husband to go to the Buddha and ask him if all her claims are correct. So he has no choice but to recover from his illness in order to do that—and the Buddha then confirms everything she had said.