Which term would best describe a cheap appearance that lacks taste?

The term that best describes a cheap appearance that lacks taste is "tawdry." This word specifically conveys a sense of gaudy, showy, or low-quality items that may attract attention but do so in a way that is perceived as lacking refinement or sophistication. Tawdry often connotes a sense of superficiality and an excess that is not tasteful, aligning perfectly with the idea of having a cheap appearance.

In contrast, the other terms imply positive attributes. "Elegant" suggests a refined beauty and tastefulness. "Classy" implies sophistication and high quality, often associated with style that is understated and tasteful. "Sophisticated" refers to complexity and refinement, often in terms of style or intellectual depth. These terms do not describe a cheap or tasteless appearance, which is why "tawdry" is the most accurate choice in this context.