First, what do you define as an "emergency" radio? Do you want something with a hand-crank for power, or something that takes batteries? For the portable, do you want something that is as small as possible, or reasonably small with great reception?

For home, GE makes an AM/FM radio that is very highly regarded for its AM tuner. But it uses 120 or batteries. You can also pick up a Grundig FR200 with the hand crank for $40. It also has a light and does shortwave. Reception is decent.

For something portable, check out the tiny radios at CountyComm.