Gary's Mod? Then yes, just get the whole orange box and garys mod, some fun stuff (had them once, great for $40).
I have Garry's Mod. It's fun. Although to truly enjoy the game mods you need items from Half Life 2 and the episodes, which means you have to buy the games. I have them, but i've never played them.
It's ok. Some gamemodes are neat but if you'd like an honest to goodness fun sandbox game just get minecraft.
