Castlevania III is the first one that hooked me, and I'm glad it did. The amazing music, awesome visual design, and its forward-thinking branching structure, and companion system make this a unique and fresh 2D platforming experience. As expected, though, this is an NES game through and through, meaning the usual assortments of "old game bullshit;" bad enemy spawns, cheap bosses and trial-and-error platforming make up a decent amount of the experience, yet it isn't so bad when using save states (the way I'd recommend playing it).