I love lululemon. I won't wear anything else to the gym. The yoga pants tend to wear because of pulling - from washing or rubbing against rough surfaces but they're comfy and flattering. I find they have something for everyone.
Most of the staff are great, others can be a bit snobby. Wish it was a bit more affordable. Items in black are also more expensive than colours, which is a bit annoying because i love black... and it's slimming - key for the gym.