Just to throw my $.02 on the heap.. I have had excellent experience with the Standard Horizon handhelds. Some generic features to look for:
x Supports rechargable or standard Alkaline batteries - this way you can always keep a pack of Alkaline batteries with you in case of emergency
x Read the fine print on the technology of the included batteries. There are multiple types of rechargable batteries out there. In order of preference and decreasing cost, Li-Ion (Lithium Ion), NiMH (Nickel Metal Hydride) and the standard NiCd (Nickel Cadmium) batteries. The newer, more expensive batteries offer better capacity with lighter weight, and will hold a charge for longer. The Li-Ion and NiMH also handle partial discharge/full charge cycles better than the NiCd batteries do. Obviously for all types of batteries, find the one with the most capacity, typically rated in mAH (mili-Amp hours) or AH (AH). Given two radios - one with every bell and whistle and NiCd batteries, and one with Li-Ion and the most basic features, I'd choose the Li-Ion every time. Its hard to use the extra bells-and-whistles with a dead battery
x Knobs instead of buttons for volume and squelch. It is much more convenient to operate a radio with knobs for volume and squelch controls, as you are always tweaking these as you use the radio.
Hope this helps!