Private Education Institutions (PEIs) allow students a second chance at higher education. If you cannot qualify for admission into local universities and are financially strapped to seek an overseas education, PEIs allow you to further your education at a much lower cost compared to studying overseas.
Most firms in the private sector recognize degrees obtained from a PEI as the degrees are conferred by the respective partner universities overseas. However, these degrees are seldom recognized or usually have stand a lower grade in the civil service.
UniSIM is is a government recognized private school that awards its own degrees. It offers a limited selection of programmes and may not be suitable for everyone. Also, it's relatively new compared to other long established degree programmes such as those by SIM-GE RMIT and SIM-GE UOL.
There is no best course available. Go find one that suits your needs.