solo in OOT at the seafurrys.
your warrior pet with your HoT, and BoD with Lich will be more then enough to make fast work of them.
the xp is great, and the potential loot is nice too.
there are serveral spots you can pull singles, but heck even if you pull a double, just FD the ADD off.
for grouping, atm LDoN in BB, or Sro is great for a nec as are poj, pod, pon, and poi.
Veksar is an other awsome zone for a necro to group or duo. if you can get a strong tank to work with you *preferably a SK or Pally* you 2 could rip the undead apart just up the ramp.