The Dursley family contains some of the most iconic characters in the Harry Potter universe. Without Harry's horrible time with the Dursleys at 4 Privet Drive, it just wouldn't be the same. It is therefore a bit surprising that of those, only Vernon Dursley has been released as minifigure, and that was back in 2002 where they were still yellow faced. Here is a flesh coloured version you can make yourself.
I've made a few custom figures from existing parts. Here is another one: Percy Weasley. I'd be keen to see an official version of him (maybe in the rumoured Harry Potter Collectable Minigure Series 2), but I think I've found a good combination of hair and head piece that captures his stern appearance in the movies well.
When I did my review of the otherwise excellent Hogwarts Express (set 75955) I commented that the use of panels on the sides of the cab (driver's cabin) was unfortunate and that there was no way for the driver to see forward either. Here's a small fix one can apply to remove those issues if desired.