Last summer I bought a Curt Class III receiver hitch for my 2007 Nissan Xterra. With the help of a friend with a garage and air tools, installation was easy. The primary reason for the hitch wasn't for towing anything. Rather, I wanted to be able to expand the carrying capacity of the truck by using a hitch mount cargo carrier.
The cargo carrier I got was this one from Harbor Freight. If you catch it during one of their sales and use a 20% coupon, you can probably snag it for about $70 - $80. I found it to be pretty well designed but at some point I might replace the screws holding it together with stainless steel screws. Assembly was pretty straightforward with a screwdriver and nutdriver.
As a compact/mid-sized SUV, the Xterra has enough room for a long weekend camping for two people. When I bring both kids, though, I need to leave the back seats up and lose about half my cargo capacity. Before I got the external cargo carrier I used a bag strapped to my roof rack. This is OK for duffle bags but is a major pain to access and kills gas mileage. In contrast, the hitch mount carrier is easy to mount and has enough space to hold a cooler, Rubbermaid Action Packer box full of stuff, a Coleman stove, and a roll up aluminum table from REI.
The major downside of the hitch mount carriers is that if you leave them unattended whatever is on them is vulnerable to theft. Also, you don't want to overload them because doing so will change the balance of your vehicle, affecting its handling.
The secondary reason for the hitch was for a bike rack. I finally ordered one this week. My girls have been after me to get one so I can take them to local trails for cycling. Now that they are beyond the little kid stage they'll be able to bike for long enough to make such trips worthwhile. I used to be into cycling but it's been years since I did more than a couple laps around my subdivision. It's a good, low impact way to get some exercise.