The US does not give money away without a reason. First off, Israel must spend the money given to it on US industries. The money given to Israel creates jobs in the US. Secondly, Israel provides a base for the US navy, US air force and if need be the US army in Israel to operate from. Thirdly, Israel provides technology to the US and real life environments to test out new technology. Israel is one of the biggest innovators of existing technology in the world. Last but not least, Israel provides intelligence to the US and is one of the US's greatest allies and not just the government, but the people as well. This is unlike Saudi Arabia, Jordan, Egypt and other Mideast nations which attack US embassies and routinely burn American flags.
Woman arrested trying to jump White House fence (Reuters)
from the article: U.S. Congress committee endorses $488 million aid to Israel