Hi Rick & Sue
( see rredbeak (Rod) & Motherhen have posted whilst I've been writing this )
I agree with Motherhen, can go on for hours
can you be self sufficient with out power in your van as you can stay many more places?
Try Pussy Cat flats camp ground just outside Pine Creek if you can, camped inside the grassed race track, right next to the club house that serves great beer, wine & food. The company was great also, really friendly care takers.
I see you list Tennant Creek as your home town, so I guess you already know about the iconic Daly Waters pub. Dinner & camp ground are busy, but worth the experience with a great feed & entertainment.
We went into Gunlom Falls June 2011. The falls were spectacular then. The road in is corrugated, but a bloke camped next to us had a lower clearance van & apparently was quite slow on the road in & out (more than likely holding up traffic as well.)
If you can camp without 240v then Mardugal Camp ground is the pick along Kakadu Hwy.
We camped new places as we moved along the hwy. If you've got Camps Australia 6 then the all the non van park camp grounds are listed there. They are all good camping spots with showers & toilets. I can't remember if you're allowed gennies as we have 3 solar panels on van.
We stayed @ Lee Pt van park un powered site whilst in Darwin. But others here on forum may have a better suggestion. Lee Pt is at least 10 k's out of main town centre. Large shopping centre not that far away.
We chose Litchfield Safari Pk, on the western side of Litchfield. Wasn't that far from most touristy stuff.
Arm yourself with lots of info brochures from the tourist info centres as there are numerous great spots to visit & not miss. You can pick up a stack from Katherine info centre.
We visited - Gunlom falls, Yellow Waters cruise @ sunrise, Jim Jim Falls & Twin Falls, Nourlangie Rock Art, Ubirr & its flood plain with more wonderful rock art & great views towards Arnhem Land, a cultural cruise up East Alligator River @ Ubirr. There's plenty of lagoons with bird life n Kakadu.
Cruise along Corroboree Lagoon was another great experience. I think you can do a barra fishing trip from Corroboree Pub. some say not to miss a great meal @ Humpty Doo pub.
Fabulous sunsets Mindil Markets in Darwin. WW2 oil storage tunnels, more military stuff along East Pt, esplanade walk & harbour precinct, the Darwin museum includes great display of cyclone Tracey, Nightcliff Sunday markets.
We also had a look @ NT Wildlife Pk for several hrs.
In Litchfield, there's Cascades, Florence Falls, Blue Rock hole, & Wangi Falls. We also visited The Lost City in Litchfield was also worth the drive into.
I'm not sure if it's the right season for it, but if you love fishing & the Barra are still there, give Daly River & a 1/2 day (or full day) fishing trip on the Daly a go. Rod had a very fruitfull 1/2 day trip with 'Mousie' - he knows where the right spots are (contact through the Daly river pub)
Many others on the forum here may have more, or better places to visit & stay at.
Enjoy your trip, we loved that area.
cheers sue