These guys do not have a huge selection of tiles, but what they do carry are nice and they really know their stuff.
I was doing a bathroom reno and wanted the classic "diner-style" hexagonal tiles for the floor - 1", and Olympia Tile did not have this size (they only had larger and smaller).
mettro source had good quality, porcelain hex. They also recommended to me a very nice, sleek looking metal edging for the subway wall tiles, as I did not want to use a bulky looking "cap" tile nor the cheap-looking standard plastic edging.
They also were able to tell me what quality grout and sealer to use to maintain my tile looking good as new.
Through many issues with my contractor, who was unfamiliar with the nicer looking edging and required more amounts of the supplies, and who also wanted to use their own low-quality concealer, Sean at mettro source was helpful at all times to help me work through the issues.
I would definitely recommend them if you want some nice tiles and good accessories.