I bought 3 sets of Tervis Tumblers from the internet, site unseen. They were getting raves from a message board I was on. These really live up to the hype. They have double walled insulation, so there is no condensation. You can use them for hot or cold drinks, and they keep them at the right temperature for a very long time. They are made out of polycarbonate, which is extremely durable.
I've had my sets for four years now, and they've been through the dishwasher many dozens of times. They still look brand new. There come in many designs, florals, butterflies, birds, and lighthouses, and many more.
I had one person tell me they thought these glases were awkward to drink out of because they are so thick at the rim, but other than that, I've had nothing but compliments. I will defintely repurchase if they ever wear out, but by the looks of things, that won't happen for a very long time.