Are there any policies that give so great benefits for so little cost, that you will always find yourself having them at maximum?
Some suggestions are Community Policing, Citizenship Tests and Race Discrimination Act. All of them decrease racial tension, which becomes a huge problem once you start attracting immigrants.
The Rural Development Grants policy is my favorite policy by far because of the low cost, increases GDP by 5% and lowers Unemployment by around 13%, in addition to other benefits. It does feel a little too good to be fair.
Maybe you could add Organic Farming Subsidies because it doesn’t cost much and other than a 6% drop to Capitalist opinion it allows you to make farmers happy without the costly Agricultural Subsidies.
Entrepreneur Investment Scheme is also low cost and increases GDP by 5.5% and Self Employed by 27%. Other than decreasing socialism (which some would say is a benefit) there is no negative effect.
By default settings, Capitalists are usually angry, unless your GDP is very high, and taxes are very low. Socialists are easier to please.
As long as you play a welfare state (which is the only way to fight off crime), policies that increase the number of Socialists, are a good thing.
Flat income tax is quite powerful as long as you counterbalance the poverty it causes with a small increase in welfare and public services. I always use it at the start to get rid of the debt quickly.