Another vote for Nak's.
I used to run Nak 300's straight into an iRiver (about $300 worth of gear). One time, I ran them on the same stand as someone with about $12,000 worth of gear. His recording sounded a little better, but just a little. Pairs have been popping up here occasionally, or post an ISO. They will run for a real long time on the internal mics (the only drawback is that the batteries cost $10-12 each, and can be a little hard to find), and you can get different caps for them, including the classic cp-4 shotgun caps.
In response to the above post about the built-in mics, I think the improvement you get just from getting the mics up above the crowd is worth the investment. I'll let other weigh in on the difference in the mics.