I think the best solution is still to keep the incumbent party
in power BUT vote in more opposition (i'd say at least 30%) to act
as a check against the incumbent party.
So far, it seems like a dual party system where there are 2
dominant parties seems to work best - one, as a check against the
other, two, to take over the other party should the country start
showing signs of problems.
Singaporeans would have loved to keep the incumbent party
forever in the government if the needs and interests of the people
are well taken care of. However, it seems that in recent
years, this trust has been severely taken advantage of.
More and more mega blunders and bad policies have brought on
countless problems to the citizens in general. If
Singaporeans were forward thinking, they will need to adjust their
mindsets to consider the possibility that the incumbent party might
one day fail to deliver what they have promised and if that were to
happen, they will need immediately another party to take over the
helm.
This scenario is highly possible given the rate of change in the
world today coupled with the complacency the incumbent party has
shown to the people in its handling of recent boo boos.
In simple terms to the layperson, voting for more alternative
voices into parliament is like buying insurance. Nobody
wants bad things to happen. But when it does, you want to
make sure you have made ample preparations to tide you through the
crisis.
Going by the events that have occured in the past years, one can
see that something is not quite right in the country. We need
to prepare ourselves for the eventuality that things can and will
change suddenly.
We need to buy "insurance". 
Another point.
Globally, things are moving faster.
Not individual's but global economic/political
issues.
The slow, slow world of yester-years is a thing of the past.
We need politicians to be hardnosed on the ground. 24/7 for the
ppl, with the ppl and by the ppl.
Not busy being adviser, ceo, director
of X nos of companies and still being an MP.
Or ministars treating parliment as place for siesta.
It's disgraceful.