Here is my personal list of the most interesting places in Nepal1. Bhaktapur. Of the three ancient capitals of the Kathmandu valley (Bhaktapur, Lalitpur and Basantapur) Bhaktapur has better preserved its medieval character and unique identitiy. Visiting Bhaktapur is like visiting the past. In addition to the main square, which includes many ancient temples, the Palace of the 55 windows, the Golden Gate, the dog-barking bell, etc., there is also the potter place, the tallest in the Valley five-roofed temple and it is a pleasure to simply wander the town's narrow old streets admiring the finely carved windows, watching the townspeople, who do not pay any attention to the tourists and go about their normal activities. In my opinion, in Bhaktapur there is much more interesting things and artistic treasures to see than Lalitpur or Basantapur cat offer. So if you have to choose between these three, go to Bhaktapur. (more about Bhaktapur)
For tourists elephant jungle rides, foot walks, boat or canoe trips are offered in Chitwan.
I have been to Chitwan three times and every time during safari I have seen rhinos. But never been enough lucky to meet a tiger, and I do not wonder: with the noise created by a few elephants and a dozen tourists sitting on them, the tiger must be a complete idiot to stay in the open. But there is no doubt that tigers are out there: there were cases when villagers were dragged off by tigers at night (because some houses don't have any doors). There was also one case when an over selfconfident tourist went into the jungle alone, without being escorted by an expert guide. And what happened? He was found later killed by a tiger. So, the fact that we do not see tigers, does not mean that they do not see us.
PS This list is for those who came to Nepal for a short visit and don't intend to go trekking as the most interesting trekking routes would make another list