Probably not the prettiest of the bunch, the EMKO EM-150 is definitely the most convection-friendly. The mesh-laden case can only be ordered from Czech Republic at this time.
The obscure Goodisory Rainbow C01 looks to be inspired by the H-FRAME Mini, and by inspired we mean it's a total ripoff of the IN WIN case. This Chinese chassis remains a decent option for great airflow.
Realan's E-U3 is specifically designed for Thin mini-ITX motherboards and passive cooling. At only 190 x 190 x 45mm the E-U3 is also the smallest chassis of our selection.
Not all Akasa cases are heat sink cases. The Cypher M is designed for active cooling (and does include a fan) but features enough vents for the ASUS PRIME N4000T and its 6W Celeron.
