General:
* Glimmering, golden, glow
* Gentle, graceful, gliding
* Giant, grand, glorious
* Gruesome, ghastly, grim
* Gorgeous, glowing, glamorous
Specific:
* Green, grassy, glade
* Gigantic, gargantuan, great
* Gallant, graceful, gentleman
* Glistening, gleaming, gems
* Groaning, grumbling, gut
Funny:
* Greedy, gluttonous, gorger
* Goofy, goofy, giggles
* Grumpy, grumpy, grouch
* Galloping, gurgling, gnome
You can also create your own by thinking of words that start with "G" and relate them to a theme or idea.