It's hard to find a pure FRS (Family Radio Service) radio anymore, but they're 14 channels (or less) and 1/2 watt (or less). No license requirement at all.

The most common is the combination FRS/GMRS radio with 22 channels and up to 5 watts. Though a license is technically required for GMRS, I have never heard of it being enforced. They're a great value these days. Make sure to get ones with the full five watts (many have less). I like ones that take AA or AAA batteries rather than rechargables. The hard-to-find feature I look for are ones with real on-off switches, like a volume knob that doubles as the on-off. Those actually disconnect all power when they're off. The ones that have push-button on-off switches have some little microprocessor running all the time, so they'll slowly kill their batteries.

Ham radio is a reasonably good option. It can get expensive, but you've got the ultimate flexibility.