[Don_Keyballs]

Well, you pretty much wrote down all you needed to convince yourself of what army you would like.

Horde Type Army = Nids, Orks, Guard (Maybe new DE)
Melee Based = Nids, Orks, DE, Choas, Etc.

Thinking that DE are probably too similar to Eldar to really want to make a change, and then your friend Orks gave you a sour taste... Nids seem to be your whats left.

 

[Don_Keyballs]

I would have to say you will get your best bang for the buck with Orks being you can probably find a lot of the pieces from the Battle for Black Reach or whatever one it is I can't remember. And like Boz said, you can use bits from other armies to really make your orks look like the have that looted feel. Giving a boy a star cannon instantly makes him a loota. I've also seen some pretty funny conversions in an attempt to stretch out left over bits into new units.

If you have lots of talent with green stuff, you can come up with some good Nid models, but over all, you'll probably have to spend that bit more then you would with Orks.