True 'flat fender' CJs are quite old, and because of that they're usually a bear to maintain and the ride quality/power is rather poor. People get into jeeps like that because they have a passion for the history. If your goal is a classic jeep to have a good time cruising around town in with light trail use those would be a good fit for sure, just be aware of the cost and time needed to keep something like that up. If you're not really that into spending your weekends tinkering with a 55 year old engine, then what Dempsey said is also great fun. We've both got 76 CJ7s, and have nothing but great things to say about them. (except his is much farther along and I get jeep envy every time I see his profile pic)
What CJ were you thinking about getting? Or what year range at least? If you aren't too familiar with them, take a second and read the Wikipedia page on 'Jeep CJ', it lays out the differences pretty well.