Just stopped by on my lunch break and they had a pretty good assortment. I was able to pick up 8 Galaxy Rasboras (Celestial Pearl Danio's) and they had a couple of German Rams, Discus, and Green Puffers as well. I can't find CPD's anywhere since they are too sensitive to keep in the larger fish store systems.
That's pretty good. Discus you don't see in big box stores. Sadly the closest petco to me is the staples mill and short pump ones.