Depending on your flavour....
Lords:
S. Mage: Well (until teclis and those undead zombie spammer came along...)the best mages within warhammer. Now still impressive..
Old bLood: depending on the build...awesome combat machine!
Heroes:
Scar-vet: hard hitting and very decent hero choice.
Priest: They are oke as well....
Skinks are an auto include....6 pts for poison wielding, screening and ahrassing units is GREAT!
Saurus warrior are our only decent core choice after that...Slow but sturdy.
As for the special:
Kroxigors are the heavy hitters (and are really good at it imho)
Terradons are the mage- and warmachinehunters. Good choice
Chameleon skinks are oke. imho not more than that.
SCOR....To expensive for a 1 wounded, 3+ AS and maybe "stupid unit"...
Rare:
Sallies baby!!
going higher in points..also the stegadon, but sallies are an auto include as well.
Good luck and "welcome to the jungle"