I know a lot of folks loved Shin Megami Tensei: Nocturne. I know a fair few who think it's the best MegaTen game of all time, and it was Nocturne's unique look and balls-hard difficulty that helped pave the way for Atlus' eventual rise to power.
But me? I hated it. Just out of high school, my body wasn't ready to recognize its greatness. Now I'll have a chance to try again, since Atlus put it out on PS2 classics, like, 2 days ago for a mere $9.99.
If some balls-hard demifiend action isn't your speed, they've also placed Dragon's Crown, Odin Sphere, Disgaea: Hour of Darkness, and Persona 3 FES on sale. I'd recommend Dragon's Crown if you've got a Vita or PS3, and Odin Sphere is still my favorite Vanillaware game of all time. And if you haven't played Persona 3 FES, shame on you! Correct that mistake now!