Its difficult to say as there were so many. The journey to the Masai Mara was a real eye opener, seeing how the Africans lived. Arriving in the Masai Mara stands out, seeing the vastness of it all and seeing our first Giraffe and Elephant. I arrived in the camp on my birthday and was really impressed. It is camping, so its not luxury, but as soon as we got there all of the staff couldn't do enough to help. Great food, a shower in the tent (if only for 3 minutes a day), your own personal wake up call with tea and coffee and a hot water bottle warming your bed up when you went to sleep. Much more special than staying in a generic 5 star hotel.
Others included seeing 2 lionesses with 3 recently born cubs, visiting the Masai village, seeing the small pride of lions just outside our camp on our morning drive and how they affected all the other animals around them. Seeing 8 giraffes all stood completely still watching them before all running away together was pretty special.