Pros
You will always have a job. No matter how bad you might be at something, you cannot get fired. You get free medical, dental and vision without having any deductions out of your paycheck. If you live on post, it's free. However the Army pays you for housing, and often times you can rent a really nice place off post, pay all the utilities and still have enough left over to cover cable and internet. When you are deployed, your paycheck (minus s.s.) is tax free.
Cons
Downsides would be deployments to Iraq every other year. There are no 8 hour work days in the Army. It's work until everything is done, which can sometimes be as much as 16 to 18 hours a day. There is no overtime pay. You cannot go on vacation when you would like. You are subjected to the whims of those over you without any say. Often times those who out rank you have an "elitist" attitude. With rank comes it's privileges is really taken to heart. You move around every 2-3 years. You don't have much say on where you get stationed. You can be called in on weekends without any compensation. You are limited in the distance you can travel from your duty station. Medical care, depending on your provider can sometimes be less than desirable.