Frankly, Panic's sound is too non-cohesive and experimental right now; they're all talented musicians, but that doesn't necessarily translate to a particularly accessible record. Comparatively, The Hush Sound has had a visible and viable progression over the course of their three albums that's shown an obvious maturity as they're coming into their own. That's what I mean by accomplishment.
I mean, I can't get Pretty Odd off my iPod, but I'm aware that there are reasons for that which aren't exactly due to it being a work of staggering genius.
Patrick Stump, though, is a different thing altogether. The songs he's put together for Fall Out Boy show the same kind of mature progression--especially interesting given the distinct genre, which Panic has never been pinned to--that THS has shown over time. The melodies and rhythms get more complex, more interesting, a little more risk-taking. They successfully bring in elements of R&B and the heavy melodic overtones of late-era Morrissey or later Cohen (in terms of musicality, not necessarily lyricism) while still retaining adherence to the genre. When you look at the things Patrick's worked on as a producer, I think it's pretty impressive that he's held onto that particular vision with Fall Out Boy while being notably experimental (from pop-punk) with other bands.
The thing about Avril is that she has had songwriting credit on most of the material on her albums from the start, which I always found rather admirable. I'm not going to lie and say I like her music, but with "The Best Damn Thing" she took the image and style she established with "Let Go" and ramped it up a notch. I can't fault her for making a good marketing decision, and while the music's not to my taste, it's in line with that image while still being something she can stand behind. So's Ashlee--that is, she's been songwriting since "Autobiography." I don't know, I certainly don't find it interesting or moving, but it's fun to dance to, and that's about all I expect from her anyway.