I haven't read all of the comments but you mentioned you love suspense and sci-fi and to see a wonderful sci-fi and a great variation of British English dialects I suggest Doctor Who! Also Sherlock, Merlin are great English series too. If you're into teen drama Skins UK is one of the best. I personally haven't watched but there's the Office UK and Shameless UK as far as I know. Call the Midwife is half drama half comedy.