In general SUV are expensive to own and operate. They cost more in gas have 4x as many moving parts and require maintenance most cars don't (2 differentials, transfer case, transmission and engine - all need oil changes). They will break more often then cars. If you can't afford to maintain them, you are in a world of heart-break. They also burn way more gas than cars. My Cherokee - which is actually shorter than my wife's Civic, burns 1.65X more gas in ideal highway conditions and almost 2x more gas in the city. If budget is a concern and you don't need (or use) 4wd, it's a big expense.
If you HAVE to have one, consider the following: If cost is an issue, look for a highly rated domestic - like a Ford Escape - as depreciation is steeper and you will pay less for a used one up front. Replacement parts are cheaper and they are more plentiful - any local mechanic can fix these. Good Japanese units, like the Pathfinder, Toyota 4 Runner, Subuaru Forester and Honda CR-V will cost you more up front and parts can be dear. The Nissan dealers in my part of the world are out to empty your pockets.
I think all things considered, the Escape is a good combination of reasonable reliabilty, quick depreciation and cheaper parts. Used Hyundias and Kias can be decent bets too.
If not towing or going in deep snow or mud, avoid truck-based units like Ford Explorer, Chey Tahoe, Jeep Liberty/Grand Cherokee, Dodge Durango, etc.
