I love that it looks like ice/glass.
1 cup water
3 1/2 cups white sugar
1 1/2 cups corn syrup
2 envelopes unsweetened drink mix, like Koolaid or something comparable (this is optional; you can use whatever flavors/colors you like, but this is the simplest option. In the picture above, I only used a tiny drop of blue gel food coloring, since it's just for decoration)
Spray a jelly roll pan or baking pan with cooking spray; set aside. (I used a 10x14, and I wouldn't go any smaller than that.)
Combine the water, sugar, and corn syrup in a medium pot. Heat over high heat, stirring constantly until all the sugar is dissolved. Bring to a full boil over high heat and boil without stirring until temperature reaches between 305 and 310 degrees. Remove from heat and wait for the candy to stop bubbling, then add flavoring/color. Pour into prepared pan and allow to sit until cooled, anywhere from 1 hour to 4 hours.
You can either 1) break it into pieces after it's fully cooled, or 2) wait until the candy has set a bit, and score it with a knife so it breaks apart easily; or 3) pour the candy into greased/nonstick molds. I broke it apart after it was cooled since I wanted a jagged ice effect, and I'd recommend putting the sheet of candy into some sort of plastic bag before breaking it, because otherwise little pieces fly everywhere. The texture is similar to Jolly Ranchers, but maybe a little less sticky; you'll need to wrap each piece individually, or they'll stick. (Some people coat the candy pieces with powdered sugar, which also keeps them from sticking, but I prefer to see the candy in its totally clear, glassy form.)