I live on King west and make the trip to the east end just to get my nails done at M nails. The ladies are incredibly friendly and funny. It is always an excellent environment and the staff are extremely accomodating to walk in's. I also love that you have your own personal nail kit which means they arent using dirty instruments that have been used on every person's foot before you that day.
I highly recommend stopping into Mnails if you are in the danforth area - you are sure to leave smiling!!!