If you're a lover of niche video game Tumblrs, here's a fantastic one: Video Game Foliage. "A blog dedicated to the beautiful and weird approximations of plants found in video games."
I came for the shrubbery, but stayed for the mention of Boku no Natsuyasumi, a Japanese series I've got a very soft spot for (I moved onto it after playing Sakura Note, a similar game about just...bein' a kid and doin' kid stuff).
That's my weird attachment though. For you, there are features on all kinds of bigger games, from Harvest Moon to Hitman. I know, it sounds like an almost fetishistic little thing to focus on, but seriously, this thing is great. Instead of just dumping pics, there's descriptions for most that make you think about video game trees like you've probably never done before.
Here, for example, is what goes along with some shots from Jet Set Radio:
Also a bush in a planter, which may be the more interesting construction. They get away with 4 quads arranged like the sides of a box to give the illusion of a volumetric shape and it works pretty well because you're moving so fast. The trees are made with 2 quads, but I suspect it's easier to trick the brain into seeing a radially symmetric or non-uniform cluster with few polys than it is to do a uniform non-radially-symmetric volume.
Video Game Foliage [Tumblr]