I agree that there is something about the sound of a cheap whistle. I've always read that you have to go through a lot of Generations to find one good one. I have a Feadog D that is pretty good. Generation brass and nickle, Walton. But I've purchased a many of Clarke Sweetone D andthey are always"spot on" Just love the sound of these.
Love the Michael Burke Session D, but it ain't a cheap whistle. But man does it sing. It was present I bought for myself and does it have an unreal sound.
Always wanted to know about the Bb whistles Carson. Can you fill me in on these?
Carson Turner said:
My whistles are Feadog (D), Generation (Bb, C, D, G), Clarke (C, D), Oak (D), and a wooden Adler in D. I tend to prefer the Generation whistles personally though the Adler has a really nice tone quality that is between a whistle and a recorder. I've considered a Low D but I have an antique "nach Meyer" 5 key wooden flute in D that is a decent sub for that purpose.
I think there's a certain folk music aesthetic that comes with those "cheap" whistles that you just don't get with some of the high-dollar whistles. I like the 'not exactly in perfect tune' timbre that comes with the likes of the Clarke and Generation whistles. Then again, I also like bagpipes and musette tuned concertina.

If you like whistles, Native American Style Flute (NAF) is a pretty fun instrument too and being pentatonic is really nice for just blowing some improv.