I liked "A Serbian Episode" and "Edge of Darkness" the most.
The former in particular had some truly disturbing implications of the mob and the BBC, and the references just wouldn't let go for the rest of the series, albeit lessening in frequency. You can still catch the occasional split-second visual reference to the former in the most recent episodes even.
The latter on the other hand was a classic monster story done so well, albeit with a twist. There would be real life death, and some very deliberate timing, but I won't spoil further, in case someone didn't see it back then, and wants to buy some cassettes, if you catch my drift.
Personally, I found the continuity wank utterly tasteless.