This is a post I made on EQVault about places to hunt and being crowded.
Some will think this as spoiler information, so if you do I will leave some
space. Hopefully people will add to this. This is for low to mid 20's.

I have been to every zone except Solusek A and B, Kedge Keep and the Red
Dragon's Lair. This is what I have found...

All times are peak times on a weeknight.

Permafrost: 18-22 people. Ok loot, but need a full party because you get
swarmed. It is dangerous for low 20's because of this fact.

Cazic-Thule: 70+ people. Great loot, but even with a full party this place
is hell on Norrath (unless you make straight for the bottom of the temple
with invis where the trains won't come). This has got to be Grand Central
Station of Norrath.

Unrest: 70+ people. Good loot, easy to work from edges and pull from inside.
Trains are usually manageable (or you can get away if you have SoW).

Najena: 15-20 people. Okay loot, easy in most areas. At low 20's keep away
from the high camped areas (Najena, Drezlna, and Bonecrusher).

Mistmoore: 20-30 people. Great loot for the brave, but also death for the
brave too. At low 20's you should stick to the familiars outside and by the
graveyard. I made the mistake of investigating a tunnel. When I turned
around and headed back to the zone I was backstabbed for 170 damage.

Upper Guk: Good experience, good loot. Actually went here at high teens. The
trains can be deadly at times, and if you don't know the way to the zone its
pretty much a slow and agonizing death. Need a full group and someone that
can root (ensnare is even better as they don't fight back when they are
ensnared.) Never fight something if you don't have to without being full on
mana and health. A simple kill can turn into a cluster*#&$@ very quickly.

Here are some outside areas. The reason the loot isn't as good is because
the risk is not as great. SoW and accelerando works outdoors, and you don't
have to worry about getting lost (too much).

South Karana: Good experience, so-so loot.

High Hold Pass: If you don't have a wizard in your group, forgot about it.
The general rule in High Hold is 'He who has the power gets the kill'. There
is no sharing here that I have seen. I usually avoid it except for an
occasional gnoll getting in my way.

East Karana: Great for levels from 16-20. Creatures that poison and that
require magic to hit give MORE experience than things that do not.
Significantly. Lower 20's you want two on one against Crag spiders. Ok loot.
A group of 4 low 20's or 2 mid 20's can kill Broon the cyclops. No loot to
speak of but good experience and bragging rights.

Everfrost Peaks: An occasional Snow Orc at this level is about the only
thing you want for experience, and not much. Good money from other things
though....

Nektulous Forest: On this side of the bridge attack the guards (greens and
yellows). If you see a Dragoon, don't ask questions just head for the zone.
Also not a good solo situation as the guards have a high range of visibility
and they gang up on you. SoW is pretty much required if you don't want to
die.

Ocean of Tears: Investigate the islands. Good experience on most.

Hope this helps.

Cwelenas, Minstrel of the 7th Chord

Angarth Bladedancer, Warrior of the 21th Tier
"Periissem ni periisem"