I have been coming to Runner's Den for years. My dad brought me here when I was 16 for my first pair of running shoes ever, and I keep going back. The staff are so incredibly knowledgeable, probably because most of them log 30+ miles a week and have the experience to do their job well. The wait can be a bit long, but that is because they pay so much attention to each customer. These guys genuinely like what they are doing and, in a world where I believe customer service is practically dead, outshine the rest of the running shoe stores around.
Another cool thing is that after buying a new pair of shoes there once, my hip started hurting and I thought it was because of the shoes, so I took them back and they fitted me for a different pair. They took back the other pair no problem. Turns out my hip pain wasn't because of the shoes (it was bursitis), but Runner's Den still took them back. So cool.