...in my opinion, anyway. Glad to hear yours in the comments (click on the category, "Great Moments in Obscure Rock 'n' Roll" to see this year's selections from which to choose). When the year started, I was skeptical I would find enough suitable choices, but as it turned out, there were so many good choices, it's hard to settle on just five, so I'm going to list some runners-up too. (By the way, you can find all these and more--and the best from prior years--on Spotify under "Brian Best of Obscure Rock 60s and 70s"; you may need to search "Bleiter" and then scroll through to find mine.)
Here's my top five:
And here are my runners-up, which just as easily could have been in the top five:
Blodwyn Pig, "It's Only Love," 1969
Frijid Pink, "Sing a Song for Freedom," 1970
You may add your choices from this year's selections in the comments.