English spoken in some accents sounds "better" in some ways. A British accent sounds cultured. A French or maybe Spanish accent, sexy. However, some accents could be said to sound "worse". A Chinese accent has a sing-song quality. A Hindu accent sounds like a person is standing on their tiptoes. A German accent sounds stern or angry.

When you turn the tables, I know from experience Spanish spoken in an English accent can sound like the person has down's syndrome or a stereotype gay lisp.

Since we have a fairly diverse population here, it would be interesting to find out how people think accents on their native language can improve or worsen the impression given by the speaker.