My partner and I stayed in Reykjavik for five nights at the Midgardur Center hotel - this place is excellent! The rooms are clean and quiet, the staff is friendly and helpful, and having breakfast included in the cost of your stay is a big plus since food in Iceland can get pricey.
The spa downstairs is a lovely perk and we both found it very clean with fresh towels, bathrobes, and slippers available.
Last, the midgardur hotel is in a super walkable part of the city. You’re two short blocks from a bus stop and a five to ten minute walk from rainbow street, shopping, and restaurants. Absolutely recommend this stay!