I don't think there is anyone that could fill his shoes. Clarkson was doing good telly (matter of opinion) back in the 80's and there is nobody that has Clarkson's wealth of experience in journalism and in the automotive industry.
Whatever you think of him and his antics, Top Gear is now dead,
I sat with my son last night and watched a re-run of the episode when they created their own mobile homes. We laughed and giggled, and I felt quite nostalgic. I think that will be his equivalent memory to the one I have of sitting down with my Dad on a Saturday and watching Big Daddy and Giant Haystacks slug it out on what was an entertainment programme purporting to be sport.