Dispatch.
Similar to other posts, perhaps it was just the time in my life (those formative teenage years), but when I heard Dispatch for the first time I was pretty blown away. All three members writing songs, swapping instruments and vocals, the harmonies, meshing of genres, etc. I'd never heard anything like it.
My group of close friends drove down to the concert at the Hatch Shell, while I was stuck at home working three summer jobs to try to pay for college. They called me during the concert and I sat by our home phone and listened to a song or two. Unfortunately, that's the closest I've come to hearing them live.