Oat groats for me were a game changer.
I do a batch in the slow cooker for the rest of the week. I like them cold but the girlfriend prefer it warmed up in the microwave.
I cook them to be less sticky and more individual grains texture, but not much.
Toppings can be anything really:
Banana, peanut butter and a bit of honey
Banana, grapes and apples
Seeds, nuts and berries
… or all of the above.