We got drek like the Tudors because it was drek we made ourselves 
Really? I've just finished watching season 3 on DVD, and thought most of the actors had Irish accents

Oh yes, apart from the actor playing Sir Francis someone-or-other, who definitely had a North American accent which leaked out every now and then. Probably Canadian then

I actually quite enjoy it. The costumes are lavish and reasonably accurate - not the usual leatherette nonsense. The crowd scenes actually have crowds in - not the usual handful of embarrassed looking extras mooching around. The CGI palaces aren't too awful. Nor is the script. Nor, certainly, are the girls
Jonathan Rhys Meyers (real name, Jonnie O'Keefe) is of course utterly ludicrous as Henry VIII.
Mind you, no more ludicrous than Ray Winstone playing the same role a few years back. That was surreally bad.
Rhys Meyers isn't a bad actor. And I suppose he has that note of unpredictable menace (possibly not entirely acting, according to reports) which is associated with Henry in the popular imagination.
Unfortunately, Dublin breaks through every time he gets cross (most of the time, in fairness).
The worst thing, of course, is that everyone knows Henry VIII was (by his middle years) a big fat ginger bloke... Whereas with his slicked-back black hair, pencil moustache, and fraying, chorus-boy looks, Rhys Meyers looks for all the world like a 1940's Italian spiv.
Overall though, I confess to liking it. Which is more than I can say for most 'historical' dramas.