Stuart MacBride is probably the most well known, he writes the Logan McRae series. They're police procedurals, gritty and dark with a few horror elements. I find his books hit or miss, when they're good, they're fantastic but they're not always good. Everyone I know seems to like his books more than I do, so maybe it's just me..
Cold Granite Stuart MacBride
A writer in the same vein would be Ed James and his Scott Cullen series. The first book in the series is free on Kindle (if you don't have a Kindle, you can always download the Kindle app to whatever device or computer you have). What I like about his books are the characters, especially the Scottish vernacular in there. Plus his plots are quite good.
Ghost In The Machine Ed James
James Oswald's Tony McLean series mixes a police procedural with elements of the supernatural. This is probably the first Scottish mystery I read and I was hooked. His first book,
Natural Causes is also free on Kindle, but also available in bookstores. I highly recommend this series, book 5 just came out in the UK and I wish I had teleporter to go over there and buy it right now.
Ian Rankin is another well-known but I've never read his books. He writes the Rebus series (which I think was adapted for TV?) and I've heard nothing but good things about him. Haven't gotten around to reading him myself, though.