The most important thing is the microphone, not the recorder. Second is a quiet room with limited sound reflecting surfaces.
The best "bang for the buck" would be a good quality USB Microphone and some decent recording software for your computer. There are a number of decent mics such as these: http://www.bluemic.com/desktop/
These, and other competing brands sell in the $50-150USD range.
If you don't have appropriate software, Audacity is free and often recommended: http://audacity.sourceforge.net/