Whereas I have not read a large amount of sutra's in their entirety, one that I have read and recited numerous times is the Sutra of the past vows of Earthstore Bodhisattva (Ksitigharba Sutra). There is great merit from reciting this sutra, especially on behalf of family members who have passed away.
The past is but a present memory or condition, the future but a present projection, and the present itself vanishes before it can be grasped.- Dilgo Khyentse Rinpoche
I've been so lazy about reading sutras. When I was a kid I dismissed many sutras (more properly many parts of sutras) as embellishments of one sort of another (you know those pesky parts that can be dismissed as "cultural embellishments"). Still, I would often find sutras in different places (sometimes even just walking down the street!).
Nonetheless I have often been partial to the Brahma Net Sutra. I'm trying to make headway on the Avatamsaka Sutra. More recently I am drawn to the Tse Do Sutra, one of the Amitayus sutras. When I was a Zen student I memorized the Heart Sutra and still frequently recite it.
I also am very fond of the Pali cannon. In many ways my favorite sutta there is the Ant Hill Sutta although many other suttas are dear to me.
I like the Vimalakirti Sutra. It seems to contain elements of humour. Thereupon, the venerable Sariputra had this thought: "There is not even a single chair in this house. Where are these disciples and bodhisattvas going to sit?"
The Licchavi Vimalakirti read the thought of the venerable Sariputra and said, "Reverend Sariputra, did you come here for the sake of the Dharma? Or did you come here for the sake of a chair?"
Sariputra replied, "I came for the sake of the Dharma, not for the sake of a chair."