I prefer Glamour to Cosmo. Although, I'm not sure exactly why. I guess the magazine feels like it has more variety month to month.
I like the makeup and hair tips that come in each magazine. But I feel the magazines are too expensive for what you get. And with the recession I feel like they are cutting the pages down. Still, it's nice to have a fun mindless read once in a while. Especially when you work hard all day and just want to relax.
I wouldn't recommend a subscription because then the magazine definitely gets repetitive. I usually get it once every 3 months. Also, DO NOT sign up for their free issue. If you do, they will call and hassel and try to bill you for subscriptions for months on end. I had to call 3 times before they stopped sending me notices that I was delinquent on an account for a magazine subscription I never received.