Toaplan goes out in a blaze of glory! Although it would be hard to call this Toaplan's best shooter (they made so many!), this is my favorite, and it's the start of the manic shooting genre. The game is hugely influential--the first to have different characters for each ship, while pioneering Cave-style game play (it is no wonder that many members of the team that made Batsugun went on to form Cave). Gameplay is perfect--just shoot, dodge and bomb. The ships are pretty fast (unlike Raiden or even Donpachi) and they have an absurd potential for being powered up. The saturn version includes both the original arcade mode and a special version that sports a smaller hitbox and some other nice features (extra bomb and shield everytime you level up!)
Eh, anyway, this is the fomula from which so many modern shmups are based, and its one hell of a game. Any saturn owner would be wise to pick it up pronto.