Well, you're talking apples and oranges, here. I mean, ... you do realize you're asking us to compare the two most drastically different services, don't you?
The Marines are the down and dirty, frontline warriors that are the first to fight in any given conflict. Of the five armed forces, the Marines have far and away the highest percentage of actual soldiers, whereas more than 90?f jobs in the Air Force are support-oriented (maintaining and directing aircraft, mission planning, computing, etc.).
My guess as to why your friends and family want you to join the Air Force is because they don't want you dead -- the Air Force is definitely the safest service.
Touching on how different the lifestyles are of those in the two branches, the Marines are real rough and tumble men who typically enjoy fighting because, by and large, that's what they're being paid to do. The men (and women) of the Air Force are typically white-collar workers from wealthier backgrounds. Since the two branches are SO different, I think a question you ought to ask yourself is "Do I want to be a gardener for the next four years of my life, or an accountant?" There are desk jobs within the Marines, but they are not the main focus of the Corps.
In making your decision, be sure to check out the two branches' recruiting websites as well as several independent sources.