We're betting you make a lot of highball-style cocktails at home. Those are the ones with a little booze and a lot of mixer (think, gin and tonic or scotch and soda). Aside from wine glasses, we consider these the most important glassware for any home bar because of how basic and versatile they are (and also because we really support gin and tonic consumption).
These particular ones are the best of the best -- made in Italy out of crystal glass.
These glasses are dishwasher safe, but please note that when using a dishwasher, we recommend a low heat setting for washing and drying as crystal is sensitive to heat. Do not wash in the extreme temperatures of a commercial grade dishwasher.