Great thread! I've got lots to listen to here.
I Am The Walrus - Spooky Tooth. The heaviest thing this 8 year old had ever heard.
Got To Get You Into My Life - Cliff Bennett and The Rebel Rousers. A pretty straight cover, and not as well produced, but given a far more authentic grind than the polite original could manage.
Every Little Thing - Yes. Already mentioned but this really deserves to be heard. Hungry young band, joyful, no rules, no pretension. Vicious.
Day Tripper/If I Needed Someone/I Want You (She's So Heavy) - Type O Negative. This is likely to divide opinion (!) but I love it. I Want You could have been written for them.