Are you wanting to buy new or used? If buying new and not leasing, definitely think about your potential needs for the next five years (or length of time the vehicle will be financed). Most sedans will fit two car seats in the back seat comfortably and most will fit three tight.
My mother-in-law had Toyota Camrys for years and swore she wasn't going to drive anything else. When we bought our 2008 Hyundai Santa Fe the dealership let us drive a Sonata home while they were getting the Santa Fe ready and we took it buy my in-laws' house and let her drive it a bit. Next thing we know, they have gone and bought her a Sonata. I don't think you could go wrong with either vehicle. We are just partial to Hyundai now because of our personal experience with the brand (and our son-in-law works for the plant in Montgomery).
Based on your price point, though, you might consider a Hyundai Elantra SE instead of the Sonata.
I would add that we still have that 2008 Santa Fe...it's what I drive back and forth to Houma, La. when I go to work. 250,000 miles and still going strong. We like it so much that now 'Huntress drives a '14 Hyundai Santa Fe. You can get into a nicely equipped Sonata for pretty reasonable money, and you can drive a new, well appointed Elantra off the lot for less than 20k.
