Longridge Fell is good fun, compact and plenty of hidden bits so great if you can ride with a local or if you’ve got a day to explore. (Strava can be helpful for finding the well-ridden routes).
Some great riding round the Trough of Bowland – Whitendale, Ouster Rake, Dunsop Breast, Beattrix Fell etc, and Waddington Fell has some decent riding from Pimlico side.
Pendle is a bit disappointing though…