Start with the wines you drink most often and how you plan to use the glasses. Varietal-specific shapes can emphasize the aromas and structure of particular wines, while universal glasses offer more flexibility for storage and entertaining. You can also compare stemmed versus stemless styles, hand-made versus machine-made glasses and dishwasher-safe versus hand-wash options.
Red wine glasses generally have larger bowls to provide more surface area for aeration and aromatic development. White wine glasses are often smaller and narrower, which helps preserve cooler serving temperatures while concentrating more delicate aromas.
Glass shape can affect how aromas collect in the bowl and how the wine reaches your mouth, which can influence the way acidity, fruit, tannin and alcohol are perceived. A varietal-specific glass is not required to enjoy good wine, but it can provide a more focused tasting experience.
Stemmed glasses keep your hand away from the bowl, helping maintain serving temperature and reduce fingerprints. Stemless glasses can be more stable, more convenient to store and easier to load in the dishwasher. The better choice depends on the wine and how you plan to use the glassware.