First of all, gcsuffer, I hope that your question is for aiming for knowledge and doesn't intend sarcasm of the benefits of the US citizenship!
But, anway, if you needed the information i will tell you a little , which is what i know about the benefits of the U.S. Citizenship :
1- carrying a US passport will provide you freedom of travel as %99 or world's countries don't require US citizens to obtain a visa to enter those countries. That could save you money too , just kiddng
.
2- By being a citizen, you can file petition for relatives and bring your family (sisters, brothers, and parents) to come and live in the US. Although the process could take a long time, but at the end , they will end up here.
3- Many government and federal jobs require US citizenship.
4- Also, some federal and State-funded grants and scholarships for higher education are offered solely to US citizens. And i am not talking about the Pell Grant which is offered to citizens and residents, but the State grants, like the one i applied, and ofcoure got denied, in Tennessee, and it's called TSA, Tennessee Student Assistance.
5- Needless to talk about your rights here as a US citizen living in the United states just like any other US born citizen, you can vote, sue, serve in a jury duty, etc..
6- You cannot be deported as a US citizen , even if you commited a major crime, unless your citizenship was provoked due to lying in the process of naturalization.
That's all for now, i might get some more later.
I hope that helps a little.