The best Mario and Luigi game out there thus far is the new "Mario & Luigi: Bowsers Inside Story". The two precedors (I spelled that wrong, didn't I?) "Mario & Luigi: Parters In Time" & "Mario and Luigi: Superstar Saga" What do you think of these games, as apposed to the more common Mario games (i.e New Super Mario Bros.)?
I played Bowser's Inside & Superstar Saga. I gotta admit, they are one of my faveorite games. Superstar Saga got stolen from me, but I'm playing Bowser's Inside right now, the Final Battle. OMG, Dark Fawful is so fudge-ing hard. xDD