I first stumbled upon Portland, ME based three-piece The Leftovers a few years back. I was immediately drawn in by their solid pop punk stylings and Beatlesque pop sensibilities, and played the hell out of their records.
Collector's Club Collection, compiled by the Collector's Club label, covers the band's best material during their active 2006-09 period and throws in a bonus demo and live cover of Woolly Bully.
I've come to know all these songs well and I think they're all great, but Gotta Go fills the slot for my favourite. Brutally simple pop punk, and all the better for it.