Music is of course the most subjective of tastes. For me a perfect album is one I can sing the entirety of from start to finish without skipping a track.

Albums such as Positive Songs for Negative People by Frank Turner, Post Electric Blues by Idlewild, ESCM by BT, Bleed American by Jimmy Eat World or Paper Walls by Yellowcard all fit this bill for me but are probably not everyone's cup of tea.