FRS - has fairly short operating distance because of low wattage. Many inexpensive radios are FRS/GRMS but you can legally only use the FRS channels without a license
GRMS - has a fairly steep license
fee ($70 at one tine but i think it has changed) for one family member that, I believe has to be the control operator. It allows more wattage than the FRS but still has limitted distance.
MURS - I have heard of these but cannot comment.
We use Amateur radio. My wife and I are both licensed. The advantage is higger wattage equating to longer communications distance. You do need to pass a rest, which is 35 questions and usually costs $15 for the test fee. Tests are given by certified volunteers, usually in a radio club. There is no actual fee for the license
and it's good for 10 years.
Radios can be purchased for as little as $30 or for as much as you can afford. It's also a great way to make local contacts in an area.
1970 Trails West Campster
2008 Honda Ridgeline