IMO, there is no "best", there is only what you like!
For instance, I use a fixed arm adjustable width $145 towbar on my Jeep. It has worked great for nearly 20 years on various vehicles. Nothing has worn out, bent or broke! SOME people say it is too inconvenient to use one of the awful things!
I have no trouble at all. I even hook it to the motorhome by myself!
I use a dolly for our PT Cruiser. Oh, sure, I could put a lube pump on it. That would only cost about $1000, plus the cost of a towbar and base plates. If it failed, a new transmission would only cost about $2500. I think I'll keep using the dolly. It worked fine for our vacation from Montana to Tennessee and back.
I have used a trailer also. It works for ANY vehicle. Some vehicles can not be towed four down, and some can not be dolly towed. ALL vehicles within the weight limits can be trailered!
As for what can be towed:
Nearly all Jeep 4X4s can be towed four down, as well as many other 4X4 vehicles that have a NEUTRAL in the transfer case shifter. Most 4X4s can not be dolly towed!
Subaru vehicles, MANUAL transmission only, can usually be towed four down. they can not be dolly towed, regardless of transmission.
Many front wheel drive manual transmission vehicles can be towed four down. They also make great dolly tows.
ALWAYS look in the Owners Manual for "Recreational Towing" Instructions for any vehicle you are considering. If the Owners Manual says NO, I would not tow it. Do not rely on what a salesman or service manager says. It is doubtful they really know anything about it!
However, some people DO tow vehicles that the manufacturer says NO for. It is their vehicle, not mine, I don't care what they do.
Again, it is personal preference. Only YOU can decide what is right for YOU.
Good luck.
EDIT: I forgot to mention towed vehicle braking. While it is a good idea, it is not required by law in many (if not most) states. Some states have "Braking Performance Laws", where you must be able to stop within a set distance, often 40 or 45 feet, from 20 MPH, on a hard, level, clean surface.
Keep in mind that a towed motor vehicle is often NOT a trailer by legal definition, and trailer towing laws do not apply.
Check the laws in YOUR state to find out what YOU need to do. Do NOT rely on any list of towing laws on the internet. Every one I have seen is inaccurate!
CM1, USN (RET)
2017 Jayco TT
Daily Driver: '14 Subaru Outback
1998 Dodge QC LWB, Cummins, 5 speed, 4X2
2 Kawasaki Brute Force 750 ATVs.
Pride Raptor 3 wheeled off-road capable mobility scooter
"When seconds count, help is only minutes away!"