All insurance are about same NTUC/Great Eastern/Prudential......
Best to buy before age 25,will be much much cheaper. If above 50 is really expensive nearly 3 to 4 time the premium with same payout.
The cheapest is CPF medisafe.
What are the problems that you are facing? It'd be easier to help if you provide more details...I use the MyShield health insurance plan from POSB bank and I think it's pretty good. You can check on the bank’s website and see if the plan offers everything you’re looking for.