I’ve often wondered that myself. I love Irish, Scottish, British, Australian, Welsh, South African, and New Zealand accents. Some will send me swooning into a tizzy. I’m an American, not sure if that matters. I sort of think of American accents as neutral, unless they are deeply Southern, or from the New York, New Jersey or Boston area. I tend to cringe at New York/New Jersey accents, find the Boston accent rather charming and I like some of the Southern sounding accents (Bill Clinton, Mike Nesmith, Bill Engvall) but if they’re too thick and twangy (Larry the Cable Guy or any of the dudes on Duck Dynasty, or the Honey Boo Boo crowd) I tend to cringe at that.
With foreign language accents, I don’t mind German, it sounds more like English to me. Japanese, especially spoken by women, which sounds softer to me, sounds very cute. Some of the Chinese languages, such as Shanghai-nese, sounds very gutteral and harsh to me. I think some of the nordic languages sound very cute, such as Danish and Swedish.
French, Spanish and Portugese, just sound foreign, but rather neutral.
Here are some examples of my favorite accents:
Example 1
Example 2
Example 3
Example 4
Example 5
Example 6 (NSFW)
Example 7
Example 8
Example 9
Example 10