Well, this is not all inclusive by any means, but I can think of one particular episode where he is directly the villain - or actually two episodes - Barbarians at the Planet and House of Luthor.
Lex plants the bomb in the replica of Jack's lunchbox and it is this bomb that blows up the Daily Planet. He also pays off the board of directors to go along with the sale of the DP to him. And indirectly through his assistant, he pays off the insurance agent who lies to Lois about how much insurance was taken out on the Planet - claiming that it wasn't sufficient for a rebuild.
So in a nutshell, I see him as directly responsible for destroying the Daily Planet which had the effects of putting both Lois and Clark out of work.
That's a start - I know there has to be more, but that is the one that comes most immediately to mind.
Hope it helps a bit.
Lynn
