I just got an Olympus VN-8100PC Digital Voice Recorder form Costco for $39.99 and I thought I'd write a quick review.
The only other recorder I've used is my Android phone so that's the my basis for comparison.
This Olympus recorder is well done and reasonably priced. It's a little bit bigger than I would have liked and too obviously a voice recorder for comfort. I'm thinking it would have been better to get an MP3 player so it isn't so obvious.
It records very well and quiet (or distant) sounds are easy to capture.
The part that ruins it for me is how it sounds when I've got it in my pocket. I can capture a conversation nicely but it is WAY too sensitive to motion. The recording is full of the sound of cloth brushing against the microphone. By comparison, my Android phone doesn't have any problem with these sounds when it's in the same pocket.
The Olympus has good volume compared to the Android phone. However, I can edit the Android recordings to increase the volume and the results actually sound better than the Olympus.
For $39.99 the Olympus is a great recorder if you can leave is sitting somewhere. If you need to cary it in your pocket the recordings will not be very satisfying.
I actually disassembled the unit I bought and tried to cushion and isolate the internal microphone with some adhesive backed foam. It improved the performance a bit but it still falls short of the sound quality of the Android phone when carried in my pocket.