All The Bells and Whistles

It's got ringers, musical tones, more than enough distinctive sounds AND even symbols for even the most needy technophile, and can be found for the price of just a single handset.
Listen to your messages over the built-in speaker phone, speakers in both handset and the base, easy to navigate menus, light, and fits most any hand.
Even has vibrate feature.
The cons are that it uses "AA" type batteries, which with all of the features used, tend to wear down fast, but you can use the base as a recharger for another set.
The Pros far out-weigh the cons, and for what you get for how little the cost is, it would even make a great gift