[quote=@Inkarnate]
Yeah, not all of Jimmy Eat World’s output is optimistic one hundred percent of the time lyrically, I think most artists are more three dimensional than that. Even evocative happiness-driven genres like twee have plenty of artists reaching into tones of melancholy, somberness, and regret.
[/quote]

Generally speaking, I think Jimmy Eat World's Chase This Light is even more optimistic and saccharine, though it's also not without it's melancholy backdrop. In fact, the sadness is what makes it so uplifting, in my opinion. I was fifteen years old when I first heard the song "Here it Goes". It talks about people not valuing you and stuff like that, but it's also one of the more encouraging songs I've ever heard.

This is reaching back to before they were a general emotive pop-punk band and closer to a general Midwestern emo band (see "Static Prevails"), but the song "Your New Aesthetic" off of Clarity is one of the most awesomest songs ever, once you get over it's deliberate disjointed nature. I'd say that Clarity is extremely optimistic because it's about growing up, getting over your problems and deciding you'll do something productive with your adulthood (see "A Sunday").

Otherwise, I don't know if I'd call this optimism or just general off-the-wall happiness, but Masked Intruder is a pop-punk band in the vain/vein of Blink-182 (but better) with the persistent shtick of assuming the guises of a crew of romantic burglars. What they say isn't always nice, but I haven't ever heard them play a sad song. Check out the EP "Love and Other Crimes".