I've been to M Nails several times now, it's my new go-to place for "cheap and cheerful" pedicures.
The staff is incredibly friendly and go out of their way to make the experience wonderful - offering green tea and bottled water, bringing magazines to you, and of course the massaging chairs.
I have had some gnarly toenails from running and they don't comment or snicker about them, which I really appreciate.
They have a good selection of polish brands and colours and as others have noted they keep a box with your own file and pumice. The one time I had a small issue with the polish application (very uneven on one big toe), they were very apologetic and went so far as redoing all of the nails (which I totally wasn't expecting).
My husband has also had pedicures at M Nails; they are just as welcoming to him and his feet look great afterwards.