Hi Julie! Depending on your budget, I definitely echo Kristi's recommendation for Matterport. I've heard nothing but great things! These 3D tours can be embedded in websites and your Apartments.com listings, and will be far more immersive than still photos.
As far as digital cameras go, I have a Sony a6500, and I love it. Full disclosure: I haven't tested other digital cameras, nor have I used my camera for apartment photos/videos - just for personal use. It's very slim, takes great high-res photos, and can also take 4k video. Depending on what lens(es) and accessories you get for it, it will likely cost $1,500-2,000.
If you have a newer smartphone and want to try a super cheap option, we recommend picking up a wide-angle lens such as this:
www.olloclip.com
. I think you'd be surprised at the quality of photos you can take with this simple setup.
Have you considered doing videos like the ones Kristi mentioned?