Triumph TT Special. They didn't make many, and they had a low survival rate. Most were raced to death. It was the bike to have in the 1960s. I couldn't afford one then, but now I have one. I built it the way it should have been done. Forged pistons, balance job, pro port and valve job with stem seals, full pressure top end oiling, and Megacycle cams. Modern sealants and proper assembly mean it doesn't leak a drop of oil.
I'll never sell it.