what kind of modest mouse do you listen to? their older stuff is a bit different than their new stuff. not snobbing or anything, just trying to get an idea of what you like.
I recommend:
wolf parade, a prayer for queen mary: nothing too complicated, just straight up keyboard and guitar driven rock.
the arcade fire, funeral: I don't particularly like this album but many people do. it got a 9.7 on pitchfork media.
the shins, chutes too narrow: pretty solid band, this album has some variety.
death cab for cutie, transatlanticism: they're on the emo side but I can see you liking them.
in general, I recommend that you go here to look for stuff:
www.pitchforkmedia.com