We had heard good things about Reykjavík Roasters from the locals so decided to visit the cafe while we were by Hallgrimskirkja church. They have a ton of coffee shops and cafes to choose from in Reykjavík, but this was probably our favorite that we visited. They have several coffee drinks to choose from. I tried a pour over and my wife had a latte. Both were great. The cafe is laid back with a few books scattered about to read. We did buy coffee beans from here to take home and for a gift.
They have multiple Reykjavík Roasters locations so you can get to one no matter where you are in the city.