To be honest, any SUV you're going to get is going to have its own separate problems.
The Cherokees have drivetrain problems, namely rear end issues. Don't forget Chrysler's never-ending electrical problems.
Fords just... no. Transmissions, electrical, timing components, you name it. I hate those things, though they make me lots of money.
Blazers are great, but have problems with intake gaskets and other relatively minor - but expensive to repair - issues.
I will say this about Fords, I drive an Expedition right now and I love it. But, it's got a problem with the transmission and it's going to cost me about 700 bucks to fix it. It also rides better than my Oldsmobile.