Well...one spot I haven't seen anyone mention is the Druids.
The best solo spot I've ever seen (went from 32-40 there in about 10 hours work) is the druids around the druid rings in WC. Now, its a hard camp, so I suggest you get a guide for it at
necro.eqclasses.com . This is the most awesome necro resource around...look in the forums, and there should be a guide somewhere.