I just bought a Uniden EXAI 7980 (900 Mhz, w/caller ID, Integrated Digital Answering Machine, Speakerphone, Extended Range) for around $70 at Amazon. I really like it, it's relatively small and has great range and sound so far.
Here are a few of the features: call waiting/caller ID, 15 minutes of digital recording time on answering machine, time/day stamp, 3-line backlit display, 30 number CID memory, new message indicator, outgoing message function and it has a pre-programmed answering message if you want to use the default. There are a bunch of other things, I'm actually still paging through the manual. It only took me about five minutes to set the thing up out of the box, but I haven't really looked at the advanced features yet.