I discovered Professor Layton with the Unwound Future which is the third game. I went back and bought the two games before that as well as the fourth game. I don't think I've ever purchased a console simply to play older games in a series though.
Of course I did go back to play older Zelda games. My first Zelda was Link's Awakening. I played Zelda 1 and 2 on the Collector's Edition and bought ALTTP on SNES (which my family always had but somehow didn't have ALTTP). I played the Mario series in order of release kind of (we had Mario Bros 1 and 3 growing up). Metroid I'm just now discovering with Metroid from the 3ds Ambassador Program and Super Metroid from the SNES Classic.
One other example would be Castlevania. I played Circle of the Moon on GBA and bought a Konami collection for Xbox 360 solely to play Symphony of the Night. I plan on playing Castlevania IV on the Super SNES Classic and will play Castlevanias 1 and 2 when the NES Classic is re-released next summer.
Of course I did go back to play older Zelda games. My first Zelda was Link's Awakening. I played Zelda 1 and 2 on the Collector's Edition and bought ALTTP on SNES (which my family always had but somehow didn't have ALTTP). I played the Mario series in order of release kind of (we had Mario Bros 1 and 3 growing up). Metroid I'm just now discovering with Metroid from the 3ds Ambassador Program and Super Metroid from the SNES Classic.
One other example would be Castlevania. I played Circle of the Moon on GBA and bought a Konami collection for Xbox 360 solely to play Symphony of the Night. I plan on playing Castlevania IV on the Super SNES Classic and will play Castlevanias 1 and 2 when the NES Classic is re-released next summer.