elite status in a frequent flyer program

I decided today that I will try to gain elite status in a frequent flyer program. I haven't decided which one, but I will soon. I discovered today that if I had flown all my flights on the same carrier, I would have earned elite status two flights ago, giving me free access to airline lounges. I speak of airline lounges because I am in one right now. My northwest ticket came with a day pass to their day lounge. The only problem was that I had to use it before July 25th. Considering that today is the last day I will be in Ohare before July 25th, I decided to use it. The lounges really make flying a much more pleasant experience. No noisy crowds or crying babies. Instead an empty chair with free drinks and snacks and free wireless. Now I just have to decide which carrier to use. American airlines services more domestic destinations but flying isn't always a pleasant experience. I definitely won't use them internationally. For international flights, I prefer swiss air and lufthansa, which share miles with united. I definitely prefer the service on united flights, but they don't service all the airports I need domestically. I'm closest to elite status on Northwest, but I really hate flying them, so I think I will avoid them for the time being. Does anyone have a suggestion for a frequent flyer club?

P.S. - If you didn't know, I'm writing this post from the Ohare airport. I flew back to the US for a wedding and now I fly back to Europe to start my fellowship. I'm sorry if I didn't call you. I was only on US soil for 48 hours so I didn't have much time to call people. We can still email. :-)