R-Type was a revolutionary shooter that seemed well ahead of it's time. Beautiful graphics, great music, a super cool ship with unique abilities, and a good ending. There are multiple endings, actually. R-Type earned a distinction from IGN as the 7th hardest game to beat. It is tough.
The TurboGrafx version is a near-perfect clone of the arcade version. The only notable difference is in sound quality, due to the different sound board.