There is something about drinking out of a fun glass that makes your beverage taste better. We learned this when we were kids and given crazy straws. Koolaid was sooo much better after it made the windy path up to my mouth. Even as an adult, I want my cabinets to have fun cups for all different occasions. Thanks to my love of coffee, I'm set on coffee mugs. Tim and I registered for funky, curved drinking glasses and after breaking a few (we're very clumsy) we decided to stick to affordable glasses. Fortunately we discovered that our Goodwil has an amazing glasswear section.
When you shop for anything used, inspect every edge of it! For glasses, I turn them over and inspect for and cracks or scratches. I double check that any detail work is still intact and that the glass feels durable. I don't care if my dishes match, but I do stumble accross complete sets - so if you're pickier about that you can still find what you're looking for.
I may not care if the dishes match, but I do want them to go together. The middle one is my favorite, but the two on the ends are similar in color, size and shape. If I was entertaining and setting up a nice presentation, I would look for these similarities when selecting cups.