I think something like the NG for all people. The summer you graduate from HS, you go off to boot camp for 6 weeks. Then, its one weekend a month, two weeks a year, Heck, we could make those days national holidays so no one is inconvenienced. Make service from 18-24, or something like that. Heck, maybe just adopt the Swiss system.
with 40% of the force on Active Duty being Guard and Reserves..the one weekend a month stuff and two weeks during the year is pretty much out the window....every General I have heard in the Reserves and Guard uses the word "when" not "if" when reffering to getting mobilized.