The Maguuma Jungle in Guild Wars: Prophecies has all kinds of cool stuff. These vine (?) houses are pretty good:
Then, in the ‘capital’ city Henge of Denravi there’s this cool lookin’ plant fountain. It’s got a lot of interesting little bits to it, it’s unfortunate that the city never really was the hub of activity it was intended to be so people barely ever saw it.
And in the Guild Wars: Factions expansion there was the Echovald Forest which was a forest of gigantic trees that, due to some Wild Magic Nonsense, were turned to solid stone and now a bunch of Asian/German goths live there.
Also I want to shoutout Seymour the talking plant from Fallout 2. You encounter a scientist who has fed a bunch of mentats to a radscorpion to try and make it super-intelligent but you find out that his original experiment was to use the drugs on a plant instead but when the plant grew it didn’t seem any different so he just put it outside in his garden. Well, it turns out the plant realized that if he showed the scientist how smart he was then he’d have to do a bunch of tests and get dissected so he pretends to be a regular plant instead! And if you ask, he teaches you how to play chess.