A compilation of some nice minimal sites that we have found lately:
1. MAKING SOFTWARE | A reference manual for people who design and build software.
→ makingsoftware.co

2. Blocks | Collection of monochromatic design explorations.
→ blocks.shawnlukas.com

3. Finta | Taxes & Accounting Simplified.
→ finta.com

4. Mesh Architects | They design great places that lift your spirits.
→ mesharchitects.co.uk

5. Google Creative Lab Five
→ creativelab5.com