With moderate thanks to the less helpful replies....

We like Southport. It's a good mix of faded grandeur and true British tat. If we want a day at the seaside over this side of the country we go there. Crosby is a better beach for interest (both the sculptures and odds and ends of rockpool), but there aren't so many opportunities for a cuppa.
I haven't got round to the OS maps for over here yet, must do that.