[support] Show/hide block on selected pages

Hello I need to show/hide a block on selected pages, I know about php code to control block visibility, and I know the Block Assign module, but: I need to show block A on selected pages and views. I need to show block B on selected pages and views. I need to show block C on the rest. I'm not shure what is the best approach to do that without a very big IF/THEN/ELSE on php. Thank's for all!