49. Castlevania III: Dracula's Curse
The best non-Metroidvania Castlevania game in the series from what I have played so far. The music, level design and bosses are top notch although the difficulty this time around is through the roof. The fact that you have four possible characters to play as in this game is probably the selling feature, they're all unique and have their own advantages and disadvantages. It's fun just to replay levels as a different character and see how it plays differently. The graphics are great too, probably some of the best on the NES and art style gives it that dark and rough feel I'd expect to find in a land infested with vampires and other monsters. I still haven't beaten this game but...one day...
Hint for 48: 3 days.