Northern Territory
 

Kakadu, Katherine Gorge or Litchfield. If you could only pick two which would they be and why?

That's easy--#1 Litchfield and #2 Katherine Gorge. First of all, Litchfield is an easy day trip from Dawrin and there are so many interesting things to see and do there. Swimming at Wangi Falls is an absolute must--it is so beautiful and the water is so refreshing. We also enjoyed Florence Falls (saw a rock wallaby on the way down to the falls) and the other pool--name escapes me now. The termite mounds are fascinating, so plan a stop at the magnetic termite mounds.
Second, Katherine Gorge was spectacular. We rented canoes (which need to be done well in advance of your visit) and got a fabulous view of the gorge in addition to a chance to stop for a nice swim. The flying foxes at the entrance are interesting too. I understand there are some good hiking trails too, but we didn't have enough time for that on our visit. If you are going to be in the area of Katherine, I can highly recommend a visit to Edith Falls National Park. There are two natural pools there--one at the entrance and another at the top of a nice hike. If you can't manage the hike, the lower pool is great--HUGE with a waterfall. There's a large grassy area also, so plan to take a picnic lunch. The locals say the park gets "crowded" on weekends, so plan to go mid-week. We did and there weren't more than a handful of people there. Also, I highly recommend the Crocodile Night Adventure in Katherine. It's not at all "hokey"--I learned a lot about crocs--and eating good food under the Milky Way was unforgettable.
Although I have been to Litchfield and Katherine twice, I would NOT repeat my visit to Kakadu. It was crowded and expensive. We were crammed like sardines on the Yellow River boat tour and even the hiking trails were full of people. There's a limited choice for accomodations and food and it's all expensive. Skip it.

Well sorry but I have to disagree with the previous poster because 1/ how could a National Park the size of Yellowstone be crowded? 2/ there are so many things and places to see and do in that area that the population of Australia would have had to be there for it to be crowded.
For my money number 1 is Kakadu and 2 Kathrine.
I do not care for Litchfield at all particularly in the dry season as there can be no waterfalls at all there, nor swimming holes for that matter.
If someone takes a trip that is not taking in places that are of the best interest then it is not right to blame the place - blame yourself.
If I were going back to Kakadu ( and I have been 4 times and I will go again) I would do it with a small company that has an all terrain vehicle, cooks its own food for you and has camping facilities. That way they take you to places that are off the "tourist trap map" and go to places that are unique in the world whilst you get all the information available about what you are seeing.
When I lived in the NT there were small tours that went to Kakadu and overland then to Kathrine. I have spent nights camping in Kakadu and the best of all were the fireflies and the stars.
I too have done the Yellow Waters trip and I would not say that I felt like a sardine. The one we did we had a bbq lunch of Buff and Barra which was wonderful. Buff is buffalo of course and Barra is the Barramundi fish which is best caught in the NT.
Sure if you decide to get on the first Greyhound bus tour of Kakadu you may feel like you are exploited in terms of cost - but look around there are some fantastic tours which really show you the best.

Ha!!!!
We would say Litchfield Number 1 and Kakadu Number 2!!!
We were travelling in December (are we made I hear you cry!) So Litchfield got number 1 spot as it was so refreshing and fun to swim in all the water holes. (it was 54 centigrade that day in our camper) We loved the termite mounds too. Kakadu was awsome. There was only us and 2 other couples on the Yellow River boat tour and our Abouriginal guide was wonderful and so enthusiastic. We saw so much wild life; Crocs, Birds and flying foxes. We loved all the Abouriginal art too and did some great walks. Oh and the tourist info centre/display was really informative.

Loved all three. Litchfield and Katherine can pretty much be seen in one day each. Difficult to compare them with Kakadu as Kakadu is much bigger and offers a significantly greater varity of things to see and do, besides the standard Yellow Waters cruise. To do it any justice, you'll need at least a couple of days in Kakadu (we stayed four). Twin Falls and Jim Jim Falls in Kakadu were much more impressive than the falls in Litchfield, though the latter were still very beautiful. We visited Kakadu in the dry season (Aug 2000). Though it was a peak time for visitors, we didnt feel the park was overly crowded. There were a fair number of people at Ubirr for sunset...but who could blame them..it is an amazing beautiful place at that time of day.