They are lovely sliced thin and grilled with olive oil.
I also make courgette pesto when I have a glut:
Chop a small onion or shallot up very small, cook well, add grated courgettes and cook until they go very brightly coloured (not too long). Remove from heat and add any herbs you have to hand. Basil, mint, thyme oregano...allow to infuse for about 20 minutes.
I keep it like this for a few days in the fridge, and either serve it with some mixed seeds to have with bread and cheese, or add it to just about everything I am cooking: tarts, quiches, pasta, risotto, egg tortilla, bread, pizza...
The original recipe was for a bread spread with this and goats cheese and all rolled up - it's lovely that way too.
Grated courgettes mixed in with minced meat will make your burgers really juicy and moist - you won't notice the courgettes but the meat will be lovely.
Hollowed out and stuffed with minced meat, bread crumbs and the bit of the courgette you removed then baked in the oven with tomato sauce.
Courgette 'bread' is a nice cakey thing in the spirit or carrot cake. Loads of recipes online.
Can you tell we always plant too many courgettes?