This is the best year for a DV trip! With it being an El Nino year, DV is going to be full of wild flowers in spring. I backpacked DV twice and it was awesome. You have to see the Race Track, the crater(forgot the name of it) Scotty's Castle if its open (it was closed due to last years flash floods), the salt flats, Sand Dunes, Old Stovepipe well's. Theirs so much to see at DV and I can go on and on. Check out Death Valley's Facebook page for current conditions and additional information. Also check out your local Library, they might have some DV road/backcountry books. Don't forget to check out the Visitor Center, its pretty cool and you can ask any Ranger what's the best off road spot(s).
My favorite spot (when I went backpacking) is Marble Canyon. You can drive most of the way there until you hit the Narrows and then hike the rest of the way to Marble canyon. ( I think it was about a 15-20 min hike from the Narrows)
Have fun and post up some pics when you can.