I had a 93 XJ with a 2.5L 4cyl that I bought in 1999 with 75,000 miles on it. It had 275,000 on it when I traded it in 2010. I drove it from St. Louis to Moab Ut at 19, and wheeled the crap out of it on a 4" lift. In those 200,000 miles, I changed probably 12 u-joints, 5 alternators, 3 starters, rusted out floorboards (twice) and a clutch.
I'd love to own another, but only as a toy that came out of the garage on nice days and to go wheel. As others have said, they're prone to leaks (improving there), and reliability can become an issue if you start modding them a ton and either don't know what you're doing, or pay someone that doesn't. With all the sensors on the newer ones, and how much they cost I would cry if I was out on a trail with one and broke. Big wheels and tires have a ton of rotational mass, and they don't stop well. I think there are much better options out there if you're wanting a family vehicle. Looking the part simply isn't worth it to me. What you get for the money is absolutely absurd, too.
That said, I see a TJ unlimited in my future. I like the longer wheel base for stability when offroading, love the way the old TJs look, and parts are very plentiful. As stated, those old 4.0s are practically bulletproof. If I'm really feeling saucy, it may be trying to find a scrambler project. Whatever it is, I'll have the tub rhino lined and won't care about it getting wet on the inside.