Residential Property

Residential units are generally easy to rent. Turnover in housing is high, so you can usually count on an ample pool of potential tenants.
Leases are generally short, especially for apartments, so you can keep pace with the rental market. This means cash flow tends to be fairly strong with a multi-unit residential property.
Financing residential property is usually fairly straightforward.
The cost per unit tends to be lower for residential than commercial. The more units you have, the less likely it is that a vacancy will severely impact your cash flow.