This semester 1 of my courses is English phonetics and intonation (focusing on RP). In Monday's lecture on different accents in English, the professor showed us this blog, so I think it's a good idea to share it here.
Additional videos to demonstrate various accents:
1/ RP speakers:
Helena Bonham Carter:
2/ These 2 have accents that sound like similar to RP, but according to my Australian teacher, because I'm not good enough to detect the features and to recognise an accent, they have traces of regional accents.
3/ Billy Boyd's Scottish accent:
Kelly MacDonald, also from Glasgow:
4/ Ricky Gervais's accent- 1 of the worst in the world:
(I don't get his sense of humour either, but that's another matter).
5/ And here, from 11:16, Miranda Richardson's horrendous accent that I can't identify in "Spider":
For American accents: http://dialectblog.com/northamerican-accents/
I myself can't tell the difference. Having seen tons of films by Martin Scorsese and Sidney Lumet I still don't see how differently New Yorkers speak from GA speakers. Except African American Vernacular English and Southern American accents, American accents generally sound the same to me.