A game that taken up much of my miniscule spare time collection is Paper Mario: The Thousand Year Door. It's the best Cube game since Metroid Prime, and probably my favourite Mario game (even though it's not an action game).

Paper Mario is a lightweight role-playing / adventure / action game with the odd conceit that everyone is a 2D paper sprite living in a 3D world. It keeps switching up the style of game throughout, so it doesn't get old, and it's very accessible even if you hate role-playing games. Two things in particular stand out about it: the music and the translation.

The music is not your standard Nintendo music, though many of the themes are based on themes from earlier games. It's composed in a style completely different from what you'd expect in a Mario game, and uses dissonance and evil clown meters to good effect. Music is never out of place, and only gets annoying in the battle scenes which have only two possible themes. This is probably one of the most effective non-ambient soundtrack I've heard on a console title.

The main reason Paper Mario is so great is that it was translated by English speakers. The dialogue is colloquial and makes sense, and even has some dry humour which is often lost in Japanese translations (which consist of everyone running around saying 'Yo' and 'hurrhurrrhurr'). Because of this, the story makes sense and is halfway decent. See any Final Fantasy title for an example of a nonsensical overdramatic storyline that gets worse through the translation, and then see this game for the way to do it right.