You were wondering about LFS in Denver. So, my favorite has definitely been Aquatic Dog. They have a great selection of plants (selection changes weekly, so it’s alwsys exciting to see what they have), some good driftwood and rocks, and a knowledgeable staff. Good ferts and planted tank supplies available, too. I got my EcoComplete substrate from them at a reasonable price. I also got my Cory’s, Otos, nerites, and tetras there.
I’ve also been to Aquatic Kingdom, which didn’t seem to have as good selection of plants, but it may fluctuate. I bought my dwarf gouramis there, and they’re thriving.
Lastly, I like Fish Den, which has a great selection of plant supplies, ferts, fish foods, although they didn’t seem to have as many live plants available. Maybe it was an off-week when I visited.
Surprisingly, I’ve had great success with the TopFin tissue culture plants available at PetSmart. They’re snail and pest-free, so there’s that. Anubias, Java ferns, cardinal plants, crypts, dwarf hair grass, and S. repens are all from there, and they’re doing great in my tank.
One last thing to consider: you can order most plants with great success. I ordered a selection of bucephalandra from buceplants.com, and they’re doing great!
Hope that helps, and good luck!