I like the original song, "Summertime Blues" by Eddie Cochran.
I even like the Rush cover from Feedback. And this excellent Kyoushirou version in Japanese. And The Who. And The Stray Cats. The Beach Boys (one my hands-down favorite bands). Even Marc Bolan and TRex! It's a can't-miss song.
But nothing compares, in my mind, to Blue Cheer:
It's oddly a cover that doesn't work as well without your brain knowing the original, but it takes that meta-song knowledge and spins it somewhere amazing. It's Quentin Tarantino-like in its ability to show you what's awesome about the original by going someone the original never, ever, could.
If you know any Summertime Blues covers I didn't mention, please add them in the comments.