Dickens wrote a (little known) masterpiece here, and it has been extremely well adapted by the BBC.
In brief, Bleak House is a tale about the injustices of the nineteenth century British legal system.
It is my opinion that Gillian Anderson is the only actress whose performance is not remarkably good. Everyone else is excellent, and puts on credible performances.
The costumes, the sets, the photography - everything is of a top notch quality.
Although the series' episodes are quite slow at first, each episode is worth watching entirely, if only to see how the story develops up to the very end.
If you enjoy period movies and television series, this should definitely be on your list to watch, if you haven't already.