The Sylvaneth book would have everything you need for a pure Tree-hugger army.
Now, you like Dinosaurs? Let me tell you, Dinosaurs are great. Seraphon is filthy with them, and it feels great ripping apart people with dinosaurs, shooting them with lazers from dinosaurs, and then trampling them with star-dinosaurs.
Seraphon is all about using your synergies to the full advantage. Almost everything we have gives bonuses, rerolls, or a modifier to another unit nearby. An Oldblood on foot and a Scar-vet on Cold One (using command ability) next to a unit of Sauras (warrior or guard) have them rerolling 1's when charging, rerolling 1's to hit and 1's to wound, when generally we wound on 3's. And that's pretty nifty.
I won't lie and say we're the best, but think about it. Do you want to paint trees, or do you want to paint DINOSAURS?
More (satirical) evidence in Seraphon's case: