I agree that the Shure mics mentioned above are good choices, multi-purpose and built to last, but I am convinced the Sennheiser mics are superior. They have a line of 'evolution microphones' that have excellent reproduction qualities, and are built to last. They are in the moderate price range. You can read about them here. I use Shure and Audix and am happy with them, but once I tried the Sennheisers, I have switched to using them as much as possible. I use 4 of the 845 models for voice or instrument mics (bodhran, banjo, fiddle, etc) and 2 of the 855s for vocals, although I suspect they would make an excellent instrument mic for whistle (they have a very fine quality for the very high frequencies). These mics cost a bit more, but are well worth the premium.