BOUTIQUE-HOMES.COM offers a curated list of small and unique vacation rentals from around the world, all are very design focused. KIDANDCOE.COM is a curated list of family friendly rentals. LUXURY RETREATS represents luxury villas hand picked and inspected by it's team, taking the uncertainty out of the vacation rental booking experience. All niche sites take care of the hard and time consuming work of sifting through thousands of rentals online to find the perfect one. Niche sites may not have the traffic that the larger sites do, but they offer value because they are referral sites that target specific groups of people.
If you operate more than one rental, or you would like to advertise on multiple sites, a separate reservation and payment system can be useful. If you used RESNEXUS (or a similar reservation and payment system), in conjunction with VRBO or HOMEAWAY you would be paying a total of $1,936 / year. AIRBNB does not allow you to advertise your personal contact information, so if you want to go that route you would need to use them exclusively for all of your needs. See below for a list of online based reservation systems.
Feel like testing the water before becoming a full time host? Try a home exchange! You get to be a host and a guest at the same time, and travel for free. If you have a rental already, swap it for a family vacation. Try HomeExchange.com, for $150 you can list your home and make bookings for one year (and if you don't do an exchange in that year you get a second year for free).