Government. At least call it a government. Israel is a democracy with an elected government. By calling it a regime you are making a transparent value judgement. As a rule of thumb, the difference between a government and a regime is that a regime does not have the legitimacy of democratic government. Thus South Korea has a government, while North Korea has a regime.

Of course, there are gray areas inbetween. I think it would have been fair to call South Africa a regime, and also Rhodesia in the Smith years, and Zimbabwe under Mugabe. That's because they have the trappings of democracy without the reality of a universal franchise.

Israel, on the other hand, has both the trappings of democracy, and the reality. There are Arab Moslems with Israeli citizenship, Christians with Israeli citizenship, as well as Jews with Israeli citizenship. They all get to vote, and their votes are all counted. Therefore, it is proper to call the elected government of Israel a government, not a regime.