Even though we could have towed more and still been under capacity, I wanted the lightest weight, most economical 4-door that could be flat towed with no modifications. Why not have a margin of error and take some of the strain off the coach if possible? Therefore, we bought a used Saturn SL2 just for use as a toad. It does the job very well, and tows easily with nothing required other than unlocking the steering wheel and putting the shifter in neutral. I really appreciate its light weight (under 2,500 lb) and ease of handling each time we tow it, and I think the coach does, too. It also gets very good gas mileage in its duties as a dinghy, which is important in the sometimes remote areas in which we've RVed. In fact, it was such a reliable, efficient little vehicle on our RV trips that I started using it around home as an everyday errand car and grocery getter, even though that was never my original intention when I bought it. Almost seven years later she is still humming along in almost daily use.
However, as others have pointed out, the idea of "best" is highly subjective, For MANY reasons, what works for others may not work for you.