A lot of Mayday Parade's early work is really upbeat, especially songs from their first record, A Lesson in Romantics. The opening track, 'Jamie All Over', is so feel-good!
Some other really stand-out upbeat songs from that album include 'Ocean and Atlantic', 'Take This to Heart', and 'Champagne's for Celebrating'. And you should also definitely check out 'When I Get Home, You're So Dead', which was on their first EP, Tales Told by Dead Friends, as well as re-recorded for A Lesson in Romantics.
And if you like what you hear, then you should think about digging into bands like The Academy Is..., Relient K, Yellowcard, Motion City Soundtrack, Taking Back Sunday, Zebrahead, and Switchfoot. They're all awesome, with loads of upbeat songs too.
To get you started, here are a couple of videos to give you an idea of what they sound like along with Jamie All Over!