I find accents fascinating too, though I hate hearing most of them. I've made a conscious effort to eliminate as much of my own accents as possible. I used to have a VERY thick Brooklyn accent when I was in high school. Took me years to get rid of it mostly. However it comes out when I'm really pissed off. That combined with my angry attitude and excessive vulgarity in that state leads my wife to call me "Dice Man" (after stand up comic Andrew Dice Clay, known for his accent and childish vulgarity)
It also comes out if I'm surrounded by people who speak that way, which I find most interesting. There's some subconscious thing that happens that accesses that lod way of speaking and I don't even realize it's happening usually until someone points it out.
But I hate almost all accents, because someone who speaks with a very thick one seems lazy and inconsiderate in my opinion. Like they don't really care if you can understand them or not. Or even get offended you cannot. I mean I know SOME cannot be helped, especially foreign people, but try.
Overall outside of my little rant, very interesting topic.
I do love English accents though. I find them to make most things just funnier. I love the differences in some of the words they use for the same things we say a different way. As a fan of some English humor (not a connoisseur mind you, but a fan) I just am amused by it in a good way.