There are literally thousands of bands that fit into the category of power pop groups. The pre-requisites are as follows:
1) Two part harmonies
2) Nice mix of acoustic and electric guitar (sometimes you can use more electric if you're trying to prove that your more rock than pop)
3) Lyrics that are a little bit sappy and a little tart at times. This is usually accomplished by writing about love and lost love and unrequited love...well you get the idea, love is certainly involved in almost all of the lyrics
4) A reputation of being good live mainly due to the stage banter between members as the guitars a re-tuned.
Don't get me wrong, I love these kinds of bands. To varying degrees you could include The Replacements, Jimmy Eat World, The Smitereens, Soul Asylum and THE POSIES in this
catergory. It's THE POSIES that probably got the tag most applied to them while they were in exsistence. Having only recorded a few records solidifed their reputation as guys who could coin a phrase and play a nice hook on the guitars. THE POSIES were one of those bands that had that one guy in your friendship circle who was a rabid fan and swore to you that they were going to be huge. My friend Scott was convinced these guys were one of the five greatest bands alive (this however, must be tempered a bit because of his undying love of Dave Matthews, someone I once really liked but over time have become lukewarm towards.)
So here are a couple of Posies songs. I really enjoy "Dream All Day" from probably their best album, Frosting On The Beater. "Suddenly Mary" shows off their softer side, with an equally catchy chorus. The third track here is "Please Return It" which was off their third record, the darker (at least for them), Amazing Disgrace.
You can also find some other gems here.