Outside the box: Unusual gameplay changes

The title field is too short to explain what I mean, so I'll explain. Basically, what would you change about the gameplay which wouldn't be champions, items, summoner spells, masteries or runes?

One which is often suggested and which I agree with would be to make towers stronger. I would also allow minions to do more damage to towers however. I'd also make baron spawn a bit later. Last but not least, I would make inhibitor towers respawn with their respective inhibitor.

This isn't about the changes I want though. I'm more curious about what other people think should be done in the same vein.