Depends on how dirty yah wanna get.. and how yah wanna check out should yer number come up.
Army.. will probably get yah pretty close to the action.. sanitary arrangements and meals ain't all that hot, but you'll probably have the best chance of expressing your opinion personally wearing the green suit.
Marines.. like the army, only a lot more vigorous in they training cycle. Chance of being one of the first to greet saddam.. pretty damn high here. Same considerations regarding hygine and meals while in the field, better chow and hygine than the army when in barracks.
Navy.. ahhh, the navy. The swabbies are very technical and highly regarded when it comes to gettin to the scene of the action. By nature, this service will provide very few days of camping out and you'll be assured of having a hot shower and a good meal on the morning your bellybutton get pasted by a flurry of french exocets. Do not despair tho...
Because the Air Force will avenge you. In the Air force you get good meals, few camp outs, good chow, warm bunks, lots of great training opportunities and the comfort of knowing the planes you fly or service were built by the cheapest bidder. If you can find them.. which as far as the Iraqi's are concerned is a very baaaad thing.
I'm sure there's a recruiting office on campus. Just look for the biggest knot of protesters.