I will say, having CB, Ham, and GMRS CB is definitely the most dead, however it is an old standard. Almost every off-roader I have ever run across has a set of FRS walkie talkies in hand, this commonality is closely followed by CB radio, GMRS and lastly Ham - not to may of us.
If you're just doing line of sight stuff, stick with FRS, its stupid easy, sounds pretty decent and you will be happy enough. This is by far the simplest option, anything mire will have you dealing with external antennas, SWR, ground planes and more. It is worth mentioning in the external antenna world that every thing works, just somethings work much, much better
If your trying to talk to truckers, turn the air purple and have the most accurate traffic updates - CB is your friend. it does have a little of the spontaneous "talking to a stranger" fun, but not near as much as Ham, most of the channels other than 19 are dead quiet but with the rise of the solar cycle you might see a little pickup in long distance propagation. I do feel compelled to mention that the FCC finds it illegal to carry on a CB contact with anyone you discover to be more than 250miles from your location, but if we are being honest - no one cares.
GRMS is great for trail comms, you can get some pretty decent range out of them and being that they are up near 460Mhz they suffer less from local noise and sunspot band conditions. in short, your gonna find it much better suited to use as trail comms than CB, they will sound clearer, have shorter antennas and reach plenty far for anything you are going to do on the trails, you do have to pay the $75 license, they do seem to actually check.
Lastly is Ham radio, undoubtably the best of all worlds considering you have access to all kinds of different frequencies and can fine tune your equipment to work exactly how you want it. Ham does have way more people available for "spontaneous contact" and is the only one I would bother to put up at house (unless you have really active GMRS near you, even then I probably wouldn't bother). All that being said, if you don't already want to get into the hobby that is radio, I wouldn't trouble yourself. I mean the tests arn't hard and it "can be cheaper" than GMRS/CB. In all honesty, I love my radios, use them every night - but if you just need trail comms, go FRS/GMRS and be done with it, its a great balance between ease of use and quality for communication for trail comms.